The human RECQ DNA helicase family is involved in genomic stability. Gene mutations of RECQL2, RECQL3, and RECQL4 are associated with genetic disorders and induce early aging and carcinogenesis. Although previous studies have reported that the level of RECQL1 expression is correlated with the prognosis of some of malignancies, the function of RECQL1 is not yet clarified. The present study aimed to examine the relationship between prognosis and the level of RECQL1 expression in epithelial ovarian cancer (EOC), and to identify the role of RECQL1 in EOC cells.
The level of RECQL1 expression was determined immunohistochemically in 111 patients with EOC who received initial treatment at Hirosaki University hospital between 2006 and 2011. Effects of RECQL1 on cell growth or apoptosis were examined in vitro using wild-type and OVCAR-3 cells (RECQL1(+) cells) and similar cells transfected with RECQL1 siRNA transfected (RECQL1(−) cells).
The level of RECQL1 expression was not related to histological type, clinical stage, or retroperitoneal lymph node metastasis, but the expression level was significantly higher (P = 0.002) in patients with recurrence than those without recurrence, and progression-free survival and complete response rate to chemotherapy were also improved in patients with RECQL1-low expression (n = 39) stage III/IV EOC (P = 0.02 and P <0.05 vs RECQL1-high expression patients (n = ), respectively). A cell proliferation and colony formation assays revealed significantly less growth of RECQL1(−) cells compared to RECQL1(+) cells. A flow cytometry using annexin V -FITC and propidium iodide (PI) staining revealed a significant increase in apoptotic RECQL1(−) cells. Cell cycle analysis showed a significantly greater distribution in subG1 phase indicating apoptotic cells in RECQL1(−) cells than in RECQL1(+) cells.
These results suggest that RECQL1 is a prognostic factor for EOC and that RECQL1 contributes to potential malignancy by inhibiting apoptosis.
Ovarian cancer; RECQL1; siRNA; Apoptosis
4-Methylumbelliferone (4-MU), a hyaluronan (HA) synthesis inhibitor, has antitumor activity in cancer cells. However, few studies have focused on its effects on ovarian cancer. The aim of this study was to investigate the effects of 4-MU on ovarian cancer and to elucidate its mechanism of action.
The HRA human ovarian serous adenocarcinoma cell line was used in this study. The effects of 4-MU on cell proliferation, migration, and invasion were determined by using in vitro assays as well as an in vivo rat peritoneal carcinomatosis model. The expression of HA synthase (HAS), CD44 HA receptor, vascular endothelial growth factor (VEGF), and thymidine phosphorylase (TP) mRNA in HRA cells was analyzed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR).
4-MU administration inhibited the growth of peritoneal tumors and significantly prolonged survival. In vitro experiments showed that 4-MU inhibited HRA cell proliferation in a dose-dependent manner, while it did not affect HRA cell invasion and migration. 4-MU significantly decreased TP mRNA expression in HRA cells. On the other hand, since HAS2, CD44, and VEGF endogenous mRNA expression levels were very low in HRA cells, it was impossible to evaluate the effect of 4-MU treatment.
These results suggest that 4-MU exerts its antitumor effect on ovarian cancer through suppressing TP expression.
4-Methylumbelliferone; Ovarian cancer; Peritonitis carcinomatosa; Hymidine phosphorylase; HRA cells
This study aimed to evaluate the prophylactic effect of goshajinkigan (GJG) on paclitaxel (PTX)-induced neuropathy and to elucidate the mechanism of action.
There was a time-dependent irreversible decrease in pain threshold in PTX group. In PTX/GJG group, pain threshold showed changes in the same level as control. Electron microscope showed that although the ganglion cells of control and PTX/GJG groups were normal, degeneration of the nucleus and swelling of the mitochondria were observed in PTX group. Expression of transient receptor potential vanilloid 4 (TRPV4) gene in PTX group significantly increased compared with that in control and PTX/GJG groups. In TRPV4 knock-out mice, no PTX-induced hyperalgesia was observed, and there was no significant difference in pain threshold between the 3 groups.
These results showed that PTX induced hyperalgesia by enhancing TRPV4 expression, and suggested that GJG might alleviate hyperalgesia by preventing degeneration of the ganglion cells and suppressing TRPV4 expression.
Paclitaxel; Goshajinkigan; Peripheral neuropathy; Degeneration of the ganglion cells; TRPV4
A phase I clinical study was conducted to determine the maximum tolerated dose (MTD) and the recommended dose (RD) of irinotecan hydrochloride (CPT-11) in CPT-11/pegylated liposomal doxorubicin (PLD) combination therapy, a novel treatment regimen for platinum- and taxane-resistant recurrent ovarian cancer.
Pegylated liposomal doxorubicin was administered intravenously on day 3 at a fixed dose of 30 mg/m2. CPT-11 was administered intravenously on days 1 and 15, at a dose of 50 mg/m2 on both days. One course of chemotherapy was 28 days, and patients were given a maximum of six courses, with the CPT-11 dose being increased in increments of 10 mg/m2 (level 1, 50 mg/m2; level 2, 60 mg/m2; level 3, 70 mg/m2; level 4, 80 mg/m2) to determine MTD and RD.
During the period from April 2010 to March 2013, three patients were enrolled for each level. In the first course, no dose-limiting toxicity occurred in any of the patients. Grade 4 neutropenia was observed in two of three patients at level 4. At level 4, the antitumor effect was a partial response (PR) in two of the three patients and stable disease (SD) in one. At level 3, one of the three patients showed PR and two had SD. At level 4, the start of the next course was postponed in two of three patients. In addition, one patient at level 4 experienced hemotoxicity that met the criteria for dose reduction in the next course. The above results suggested that administration of CPT-11 at dose level 5 (90 mg/m2) would result in more patients with severe neutropenia and in more patients requiring postponement of the next course or a dose reduction. Based on the above, the RD of CPT-11 was determined to be 80 mg/m2.
The results suggest that CPT-11/PLD combination therapy for recurrent ovarian cancer is a useful treatment method with a high response rate and manageable adverse reactions. In the future phase II study, the safety and efficacy of this therapy will be assessed at 80 mg/m2 of CPT-11 and 30 mg/m2 of PLD.
Recurrent ovarian cancer; Chemotherapy; CPT-11; PLD
Estrogen causes proliferation of ovarian cancer cells. Although hormone therapy with an anti-estrogen agent is an optional therapy for recurrent epithelial ovarian cancers, both basic and clinical researches are insufficient. We here examine the efficacy of an aromatase inhibitor (AI) for peritonitis carcinomatosa, the late stage of ovarian cancer.
Estrogen receptor (ER)α was assayed in four ovarian cancer cell lines by the RT-PCR method. Using ovariectomized nude mice, peritonitis carcinomatosa consisting of OVCAR-3 cells with the strongest ERα expression or DISS cells with weaker ERα expression was prepared. The survival period was compared between the letrozole group (5 mg/kg/day orally; n = 10) and the control group (n = 10). In addition, the degree of angiogenesis and occurrence of apoptosis were compared using tumor tissue from the abdominal cavity. The expression of aromatase and the protein involving in ERα signaling were examined in tumors immunohistochemically.
Survival period in OVCAR-3 tumors was significantly prolonged in the letrozole group, compared with the control group (P < 0.05), whereas that in DISS tumors was not different between the both groups. The microvessel density in tumors and expression of VEGF decreased significantly in the letrozole group compared to the control group. The incidence of apoptosis did not differ significantly between these groups. No adverse event was observed accompanying the administration of letrozole. The expressions of aromatase, ERα and FOXP1 that is associated with ERα signaling were reduced in tumors by letrozole administration.
Letrozole was effective for ovarian cancers with abundant expression of ERα. Inhibition of angiogenesis and of ascites production appeared to contribute to prolongation of the survival period.
Recurrent ovarian cancer; Letrozole; Estrogen receptor alpha; Aromatase inhibitor; Anti-angiogenesis
Loss of ARID1A is related to oncogenic transformation of ovarian clear cell adenocarcinoma. The present study was conducted in epithelial ovarian cancer of all tissue types to investigate whether an increased or decreased expression level of ARID1A can be a prognostic factor for ovarian cancer or can influence the sensitivity to anticancer drugs.
The expression level of ARID1A was investigated in 111 patients with epithelial ovarian cancer who received initial treatment at the Hirosaki University Hospital between 2006 and 2011. The expression level of ARID1A was immunohistochemically graded using staining scores, which were calculated by multiplying the staining intensity of the nuclei by the stain-positive area.
The level of ARID1A was significantly lower in clear cell adenocarcinoma than in other histologic types. Among the patients with stage III, IV cancer (n=46), the level of ARID1A was significantly lower (p=0.026) in patients who did not achieve complete response (CR; n=12) than in patients who achieved CR (n=34). The level of ARID1A was relatively lower (p=0.07) in patients who relapsed after achieving CR (n=21) than in patients who did not relapse (n=13). When the staining score of 0 was defined as ARID1A-negative and other staining scores were defined as ARID1A-positive, there was significant difference in progression-free survival between ARID1A-negative (n=11) and ARID1A-positive (n=35) patients in stage III, IV disease.
The result suggests that decreased ARID1A expression is correlated with chemoresistance and may be a predictive factor for the risk of relapse of advanced cancer after achieving CR.
ARID1A; Chemoresistance; Epithelial ovarian cancer; Relapse
The standard postoperative chemotherapy for epithelial ovarian cancer is a combination therapy including platinum and taxanes. The aim this study was to investigate the degree of platinum sensitivity in patients with relapsed epithelial ovarian cancer according to the treatment-free interval (TFI) and the histological tumor type. The medical records of 405 patients diagnosed with stage III/IV ovarian cancer, including 107 patients who relapsed after attaining a clinical complete response with first-line treatment, were retrospectively reviewed. The degree of platinum sensitivity was assessed by comparing the progression-free survival (PFS) following the second-line treatment. In patients with serous/endometrioid adenocarcinoma who were treated with platinum following relapse, there were significant differences in the PFS between the following groups of patients: those who relapsed within 6 months and those who relapsed between 6 and 12 months; those who relapsed between 6 and 12 months and those who relapsed between 12 and 18 months; and those who relapsed between 12 and 18 months and those who relapsed after 18 months. By contrast, in patients with clear cell/mucinous adenocarcinoma who were treated with platinum following a relapse, there were no significant differences in the PFS between patients who relapsed within 6 months and those who relapsed between 6 and 12 months, while there were significant differences in the PFS between those who relapsed between 6 and 12 months and those who relapsed after 12 months. With regard to the patients who relapsed after 12 months, the PFS of those with clear cell/mucinous adenocarcinoma was significantly shorter compared with the PFS of those with serous/endometrioid adenocarcinoma. Therefore, we considered it justified to classify patients with clear cell/mucinous adenocarcinoma who relapsed within 12 months as platinum-resistant and those who relapsed after 12 months as platinum-sensitive.
relapsed epithelial ovarian cancer; platinum sensitivity; treatment-free interval; progression-free interval; histological type
Primary small cell carcinoma of the vagina is quite rare, and a standard treatment has not been established yet. Herein, we report a case of an 81-year-old woman who was diagnosed with a vaginal tumor without continuity with the uterine cervix. Histopathological diagnosis indicated alveolar solid growth of nuclear chromatin-rich atypical cells with a high N/C ratio and a partially recognized rosette-like structure, suggesting a differentiated neuroendocrine system. Chromogranin A and synaptophysin were positive. Stage I vaginal small cell carcinoma localized to the vagina was diagnosed. The tumor disappeared by radiation monotherapy with external beam irradiation and endocavitary irradiation. The patient remains alive without any disease 1 year and 8 months after the treatment, suggesting the efficacy of radiotherapy in small cell carcinoma of the vagina.
small cell carcinoma of the vagina; radiotherapy
ARID1A is a recently identified tumor suppressor participating in chromatin remodeling. Somatic inactivating mutations of ARID1A and loss of its expression occur most frequently in ovarian clear cell and endometrioid carcinomas and uterine endometrioid carcinomas. Since endometriosis is thought to be a precursor of most ovarian clear cell and endometrioid carcinomas, we undertook an analysis of ARID1A expression of these tumors arising within an endometriotic cyst (endometrioma).
Our immunohistochemical study set consisted of 47 endometriotic cysts containing clear cell carcinoma in 24 cases, well-differentiated ovarian endometrioid carcinoma in 20 and mixed clear cell and endometrioid carcinoma in 3.
ARID1A loss was observed in 31 (66%) of 47 carcinomas and therefore these cases were informative for determining the temporal sequence of loss of ARID1A expression in tumor progression. In 16 of the 47 cases, ARID1A immunoreactivity was retained in both the endometriotic cyst and the carcinoma and thus these cases were not informative. All of the 31 informative cases showed loss of ARID1A immunoreactivity in the carcinoma and in the endometriotic cyst epithelium in direct continuity with the carcinoma but not in the cyst epithelium that was not adjacent to the tumor.
The findings in this study provide cogent evidence that loss of ARID1A function as shown by loss of expression, presumably due to mutations, is an early molecular event, occurring before malignant transformation, in the development of the majority of ovarian clear cell and endometrioid carcinomas arising in endometriomas.
The role of hormone therapy in the treatment of ovarian cancer is not clear. Data on the efficacy and safety of antiestrogens and aromatase inhibitors in recurrent ovarian cancer have been accumulated through phase II clinical studies. Most of these studies were conducted in platinum-resistant recurrent ovarian cancer, and although complete response rates were not high, reported adverse events were low. If administered to patients who are positive for estrogen receptors, hormone therapy may become a viable option for the treatment of recurrent ovarian cancer.
Recurrent ovarian cancer; Hormone therapy; Letrozole; Anastrozole; Tamoxifen; Fulvestrant
The efficacy of radiotherapy (RT) for adenocarcinoma (AC) is controversial, although patients with AC of the uterine cervix are treated in a similar manner to those with squamous cell carcinoma (SCC). This retrospective study was conducted to evaluate the efficacy of adjuvant RT for patients with AC compared to those with SCC following radical hysterectomy. A total of 820 patients with stage IB-IIB cervical cancer, who underwent type III radical hysterectomy between 1997 and 2003, were retrospectively examined; the sample included 280 patients with AC and 540 with SCC. A total of 139 patients with AC and 327 with SCC underwent adjuvant treatment. The histological type did not affect the outcome for patients with stage I disease; however, stage II patients with AC exhibited a significantly worse 5-year overall survival (OS) rate compared to those with SCC. Patients with SCC exhibited significantly higher lymph node involvement compared to those with AC in stage IB1; however, there were no differences between stages IB2 and II. Among patients with lymph node involvement, patients with AC exhibited a significantly worse 5-year survival rate compared to those with SCC (46.4 vs. 72.3%, respectively; P=0.0005). Among patients receiving adjuvant RT, those with AC recurred more frequently compared to those with SCC, particularly in the pelvic cavity, including the vaginal stump and/or pelvis (24.6 vs. 10.5%, respectively; P= 0.0022). By contrast, the histological type did not affect the incidence of recurrence in paraaortic lymph nodes and/or distant recurrence. In conclusion, RT may not suffice as an adjuvant treatment for patients with cervical AC following radical hysterectomy.
adenocarcinoma; squamous cell carcinoma; uterine cervix; radiotherapy
Granulosa cell tumors (GCTs) of the ovary account for 2 to 5 of ovarian malignancies. We present two patients with malignant ovarian adult GCT. In one patient, a combination of bleomycin, etoposide, and cisplatin was effective after initial surgery for malignant GCT. In the other, an aromatase inhibitor was effective for recurrent malignant GCT. We also review the literature for further management of this tumor. Because GCT of the ovary is rare, it will be necessary to elucidate the clinical phenotype and establish treatment protocols by accumulating and analyzing more patients.
Ovarian malignant granulosa cell tumor; BEP combination therapy; Aromatase inhibitor
The present study investigated tumor proliferation in a tumor model using murine ovarian cancer cells with increased carbonyl reductase (CR) expression.
CR cDNA was transfected into murine T-Ag-MOSE ovarian cancer cells by lipofection. CR-transfected cells (CR induction group) or empty vector-treated cells (control group) were injected into the backs of 8-week-old nude mice at a concentration of 0.5 × 106 per 0.2 mL. Subsequent tumor proliferation in both groups was observed for 5 weeks.
The control group showed an increase in tumor volume during the 5 weeks of observation. However, tumor volume in the CR induction group increased up to the second week but then decreased continuously until the fifth week of observation. The tumor growth curves for the two groups showed a significant difference (Mann-Whitney U test, P < 0.001). Histological and biochemical experiments were performed using tumor tissues isolated in the third week. Necrosis and inflammatory cell infiltration were noted for tumors in the CR induction group. Also, the number of apoptotic cells was significantly increased in the CR induction group compared with the control group (P < 0.001). Milk fat globule EGF factor 8, an “eat-me” signal for phagocytes such as macrophages, was expressed extensively in the tumor cytoplasm and interstitial cells of the CR induction group, and engulfment of apoptotic cells by macrophages was observed. Vascular endothelial growth factor expression in tumors was notably decreased in the CR induction group compared with the control group.
Increased necrosis due to engulfing of apoptotic cells by phagocytes attracted by increased milk fat globule EGF factor 8 was considered to be the mechanism of spontaneous tumor regression in the CR induction group.
apoptosis; carbonyl reductase; ovarian tumor; phagocytosis