Involvement of autocrine CXCL12/CXCR4 system in the regulation of ovarian carcinoma cell invasion.

Ovarian carcinomas are often highly invasive, especially in the peritoneal cavity; however, the mechanism involved in invasion is not yet fully understood. In the present research, we studied the role of NF-κB in the invasiveness of ovarian carcinoma cells by using (-)-DHMEQ, a specific inhibitor of NF-κB. (-)-DHMEQ inhibited invasion in vitro and the expression of CXCL12 and CXCR4. We found that neutralizing antibody against CXCR4 or knockdown of CXCR4 suppressed the invasion. Proteomic analysis revealed that CXCR4-siRNA treatment lowered the secretion of several invasion-related proteins, such as MMP-9 and uPA. These data imply that (-)-DHMEQ suppressed ovarian cell invasion via inhibition of the NF-κB-regulated autocrine system of CXCL12-CXCR4.

Analysis of a correlation between the BRAF V600E mutation and abnormal DNA mismatch repair in patients with sporadic endometrial cancer.

Point mutations of KRAS and BRAF genes are thought to be important in carcinogenesis of colon cancer. In particular, gene instability caused by decreased expression of the hMLH1 gene, a DNA mismatch repair (MMR) gene, may be linked to the activating BRAF V600E point mutation in sporadic colon cancer. However, a consensus has not been established regarding the correlation between point mutations of KRAS or BRAF and carcinogenesis in patients with endometrial cancer, which is closely related to colon cancer. Therefore, we analyzed aberrant hypermethylation of the hMLH1 gene, microsatellite instability (MSI), and point mutations of KRAS and BRAF in 44 samples of sporadic endo-metrial cancer, with the aim of examining the mechanism of carcinogenesis in patients with endometrial cancer. Aberrant hMLH1 hypermethylation was found in 17 of the 44 cases (38.6%) and showed a significant positive correlation with MSI (p=0.02). This suggests that an abnormal MMR mechanism plays an important role in carcinogenesis of sporadic endometrial cancer. Point mutation of KRAS was found in 6 of the 44 cases (13.6%), but no BRAF V600E mutation was detected. These data suggest that the BRAF V600E mutation is not the target gene for abnormal MMR in carcinogenesis in patients with sporadic endometrial cancer, unlike in colon cancer. This is supported by the relatively few previous reports indicating a correlation between endometrial cancer and the BRAF V600E mutation. Identification of new candidates for the target gene for abnormal MMR in endometrial cancer requires further work.

Establishment of an ovarian metastasis model and possible involvement of E-cadherin down-regulation in the metastasis.

Clinical observations of cases of ovarian metastasis suggest that there may be a unique mechanism underlying ovarian-specific metastasis. This study was undertaken to establish an in vivo model of metastasis to the ovary, and to investigate the mechanism of ovarian-specific metastasis. We examined the capacity for ovarian metastasis in eight different human carcinoma cell lines by implantation in female NOD/SCID mice transvenously and intraperitoneally. By transvenous inoculation, only RERF-LC-AI, a poorly differentiated carcinoma cell line, frequently demonstrated ovarian metastasis. By intraperitoneal inoculation, four of the eight cell lines (HGC27, MKN-45, KATO-III, and RERF-LC-AI) metastasized to the ovary. We compared E-cadherin expression among ovarian metastatic cell lines and others. All of these four ovarian metastatic cell lines and HSKTC, a Krukenberg tumor cell line, showed E-cadherin down-regulation and others did not. E-cadherin was then forcibly expressed in RERF-LC-AI, and inhibited ovarian metastasis completely. The capacity for metastasizing to the other organs was not affected by E-cadherin expression. We also performed histological investigation of clinical ovarian-metastatic tumor cases. About half of all ovarian-metastatic tumor cases showed loss or reduction of E-cadherin expression. These data suggest that E-cadherin down-regulation may be involved in ovarian-specific metastasis.

A heavily pretreated patient with recurrent clear cell adenocarcinoma of the ovary in whom carcinomatous peritonitis was controlled successfully by salvage therapy with gemcitabine.

INTRODUCTION: Advanced clear cell adenocarcinoma of the ovary is a histologic type with an extremely poor prognosis. No reports have been published concerning useful drugs for salvage chemotherapy for this type of cancer. We performed salvage therapy with gemcitabine in a patient with multiple-drug- resistant, unresectable recurrent clear cell adenocarcinoma of the ovary and succeeded in stabilizing recurrent lesions and controlling carcinomatous peritonitis. CASE REPORT: A 55-year-old woman was in Stage IIIc of clear cell adenocarcinoma of the ovary. She had recurrent tumors after primary cytoreductive surgery, which were unresectable and also resistant to paclitaxel, carboplatin, irinotecan, and oral etoposide. After three courses of fourth-line chemotherapy with gemcitabine for the treatment of carcinomatous peritonitis and hepatic and splenic metastatic lesions, serum CA-125 and the severity of ascites showed marked decreases, and its efficacy for the hepatic and splenic metastatic lesions was classified as 5-month stable disease. The toxicity of this drug was in the acceptable range. CONCLUSION: Gemcitabine is also useful for heavily pretreated clear cell adenocarcinoma of the ovary. It is necessary to consider the use of drugs without cross resistance to platinum and taxanes in the selection of drugs for this cancer.

Epigenetic inactivation of the CHFR gene in cervical cancer contributes to sensitivity to taxanes.

A relationship between inactivation of mitotic checkpoint genes and sensitivity of cancer cells to anticancer agents has been reported. We investigated the effect of epigenetic inactivation by aberrant hypermethylation of the mitotic checkpoint gene CHFR (checkpoint with forkhead and ring finger) on the sensitivity of cervical cancer cells to taxanes. Methylation-specific PCR (MSP) of cervical smears showed aberrant methylation of CHFR in 12.3% (2/14) of adenocarcinoma specimens. In contrast, aberrant DNA methylation was not detected in normal cervical cells or squamous cell carcinoma cells. Aberrant methylation of CHFR was also analyzed in 6 human cervical carcinoma-derived cell lines and was observed in SKG-IIIb and HeLa cells. These cell lines showed high sensitivity to taxanes, but became taxane-resistant upon treatment with 5-azacytidine. Furthermore, suppression of CHFR expression in siRNA-transfected SKG-IIIa cells caused increased sensitivity to taxanes. In conclusion, aberrant methylation of the CHFR gene may be useful as a molecular marker for selection of therapy for patients with cervical adenocarcinoma with a poor prognosis, and may also suggest a new therapeutic strategy of targeting CHFR in cervical cancer. To our knowledge, this study is the first to examine epigenetic inactivation by aberrant hypermethylation of CHFR in cervical cancer.

Use of the collagen gel droplet embedded drug sensitivity test to determine drug sensitivity against ovarian mature cystic teratoma with malignant transformation to adenocarcinoma: a case report.

BACKGROUND: The collagen gel droplet embedded drug sensitivity test (CD-DST) is a new anticancer drug sensitivity test that only requires a small number of cells. We report the use of this test in the choice of adjuvant chemotherapy for treatment of a rare case of ovarian cancer involving malignant transformation of ovarian mature cystic teratoma. CASE REPORT: The patient was a 70-year-old female with an ovarian tumor, pleural effusion, carcinomatous ascites and a chest wall tumor. The histopathological diagnosis was adenocarcinoma, mature cystic teratoma with malignant transformation, stage IV. Paclitaxel/carboplatin therapy was selected as adjuvant chemotherapy based on CD-DST results. Upon completion of 6 courses, no increases in carcinomatous ascites or recurrent lesions were evident, and the chest wall tumor had disappeared completely. CONCLUSION: The CD-DST may be particularly useful for selecting preoperative chemotherapeutic drugs for patients with ovarian cancer in which the histological type of the primary tumor is unknown.

Hypermethylation in the p16 promoter region in the carcinogenesis of endometrial cancer in Japanese patients.

BACKGROUND: p16 has been reported to disappear by hypermethylation in various cancers. However, the relationship between the frequency of hypermethylation of p16 and the mechanism of its inactivation has not been completely elucidated in endometrial cancer. MATERIALS AND METHODS: Hypermethylation in the promoter region of the p16 gene and the expression of the p16 protein in 51 specimens, including 8 endometrial cancer cell lines, 7 normal endometrial tissues, 12 atypical endometrial hyperplasia tissues and 32 endometrial cancer tissues were analyzed. RESULTS: Five out of 8 endometrial cancer cell lines showed hypermethylation with high frequency, although only 1 showed loss of gene expression. However, no endometrial cancer tissue of the 32 specimens showed hypermethylation. Furthermore, loss of expression was immunohistochemically observed in 3 out of the 20 specimens. CONCLUSION: These results suggest that hypermethylation of p16 rarely occurs and, thus, has no significant effect on the carcinogenesis of endometrial cancer in Japanese patients.

Successful analysis of anticancer drug sensitivity by CD-DST using pleural fluid and ascites from patients with advanced ovarian cancer: case reports.

In vitro anticancer drug sensitivity tests have been performed for various types of cancers, and a relationship with clinical response has been observed. The collagen gel droplet-embedded culture drug sensitivity test (CD-DST) is a new in vitro anticancer drug sensitivity test by Yabushita et al., recently reported to be useful in ovarian cancer. CD-DST allows analysis of a small number of cells, compared to other anticancer drug sensitivity tests. Here, we report a successful analysis of anticancer drug sensitivity by CD-DST using cancerous ascites and pleural fluid samples from 2 patients with advanced ovarian cancer. To our knowledge, this is only the second report of the application of CD-DST in ovarian cancer, and our results suggest that CD-DST could be helpful in the selection of anticancer drugs for neoadjuvant chemotherapy in advanced ovarian cancer.

Clinical characteristics of prognostic factors in poorly differentiated (G3) endometrioid adenocarcinoma in Japan.

BACKGROUND: It has been reported that prognosis is less favorable in poorly (G3) differentiated endometrioid adenocarcinoma than in well (G1) or moderately (G2) differentiated endometrioid adenocarcinoma. The goal of this study is therefore to analyze the prognosis of G3 endometrioid adenocarcinoma and various factors that may predict a favorable prognosis. METHOD: This study included 699 Japanese cases of endometrioid adenocarcinoma at the International Federation of Gynaecology and Obstetrics (FIGO) surgical stages I-IV (including 74 G3 cases). We investigated the G1-G3 survival rates of endometrioid adenocarcinoma cases and the G2 and G3 disease-free periods. We also examined the clinicopathological characteristics of G3 endometrioid adenocarcinoma. RESULT: The prognosis was poor in stages III and IV in G3 and in G2 cases, but recurrence was observed more frequently in G3 cases than in G2 cases. Adnexal metastasis and high pre-surgery CA602 values showed significantly low P-values for survival. CONCLUSIONS: We suggest that the risk of late recurrence is higher in G3 than in G2 cases. The absence of adnexal metastasis and low pre-surgery CA19-9 values may suggest a relatively favorable prognosis in G3 endometrioid adenocarcinoma.