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1.  Dysgerminoma developing from an ectopic ovary in a patient with WAGR syndrome: A case report 
Molecular and Clinical Oncology  2016;5(5):503-506.
WAGR syndrome is caused by an 11p13 deletion and includes Wilms' tumor, aniridia, genitourinary anomalies and mental retardation. We encountered a case of a dysgerminoma originating in an ectopic ovary in a woman with WAGR syndrome. Our patient was a 24-year-old nulliparous woman who was diagnosed with WAGR syndrome. The patient had undergone left nephrectomy for a Wilms' tumor and postoperative chemotherapy at the age of 7 months. She also had a history of glaucoma surgery in both eyes, and was followed up at the Department of Pediatrics for diabetes mellitus, hypertension, liver dysfunction and hyperuricemia. The patient was investigated for oliguria and had elevated levels of blood urea nitrogen (45 mg/dl) and creatinine (5.4 mg/dl); she was admitted to the hospital with acute renal failure and a computed tomography scan revealed a pelvic tumor with a long axis of 10 cm that was obstructing the right ureter. Following insertion of a ureteral stent, the tumor was removed. The tumor had developed in the retroperitoneal space independent of the ovaries. The right adnexa were normal. The tumor was histopathologically diagnosed as dysgerminoma. Follicles were found in part of the tumor; it was thus hypothesized that the tumor developed from an ectopic ovary. The patient was administered etoposide after surgery, and has been recurrence-free for 4 years since treatment.
PMCID: PMC5103847  PMID: 27882234
WAGR syndrome; ectopic ovary; dysgerminoma; surgery; etoposide
2.  Streptococcal Toxic Shock Syndrome: Life Saving Role of Peritoneal Lavage and Drainage 
We encountered a case where an infection with group A streptococcus (GAS; ie, Streptococcus pyogenes) initially caused primary peritonitis and then subsequently caused streptococcal toxic shock syndrome. The patient’s life was likely saved by an emergency laparotomy followed by extensive peritoneal lavage and drainage.
A 40-year-old woman was admitted to the Emergency Department for lower abdominal pain and numbness in the extremities. She presented with systemic inflammatory response syndrome. An emergency laparotomy was performed, and ascites that resembled pus and general peritonitis were noted. Peritoneal lavage and drainage were performed, and GAS was isolated from peritoneal fluid. Gram staining of cervical polyp specimens revealed Gram-positive bacteria.
The patient was diagnosed with streptococcal toxic shock syndrome due to an ascending GAS infection originating from vagina.
PMCID: PMC4991574  PMID: 27579001
ascending infection; emergency laparotomy; group A streptococcus; peritoneal lavage and drainage; streptococcal toxic shock syndrome
3.  FOXP1 forkhead transcription factor is associated with the pathogenesis of endometrial cancer 
Heliyon  2016;2(5):e00116.
Endometrial cancers are mostly estrogen-dependent. FOXP1 is a P subfamily of forkhead box (FOX), and known as an estrogen-responsive transcription factor. The aims of this study were to examine histological location of FOXP1 in normal and malignant endometrium, and to investigate a possible association between FOXP1 and other factors considered to be involved in pathogenesis of endometrial cancer. The levels of FOXP1, estrogen receptor (ER)α, and ERβ expression were examined immunohistochemically in normal and malignant endometrium obtained from 75 women (8 normal, 8 atypical endometrial hyperplasia, and 59 endometrial cancers from grade 1 to 3). The effects of estrogen on ERα, FOXP1, KRAS, and PTEN expression were analyzed in telomerase-immortalized human endometrial stromal cells (T HESCs) by Western blotting. Western blotting was also used to examine the effect of FOXP1 plasmid DNA or siRNA transfection on KRAS and PTEN expression in Ishikawa cells (well differentiated endometrioid adenocarcinoma), HEC-50B cells (poorly differentiated endometrioid adenocarcinoma), and T HESCs, respectively. FOXP1 was expressed in normal and malignant endometrium, but the rate of expression was different depending upon menstrual cycle and pathological grade of malignancy. FOXP1 expression in nucleus and cytoplasm of grade 3 endometrioid cancers was significantly lower than that of grade 1 and 2 ones. Estradiol increased levels of FOXP1 and KRAS expression in a dose- and time-dependent manner in T HESCs cells, and FOXP1 transfection or knockdown led to increase or decrease of KRAS expression but not PTEN. KRAS expression level was significantly related to FOXP1 and ERα levels in cancer tissues. Estradiol did not affect KRAS expression in T HESCs cells transfected with FOXP1 siRNA. These results suggest that FOXP1 is involved in estrogen dependent endometrial cancers through KRAS pathway.
PMCID: PMC4946217  PMID: 27441287
Medicine; Cell biology
4.  Prognostic role and implications of mutation status of tumor suppressor gene ARID1A in cancer: a systematic review and meta-analysis 
Oncotarget  2015;6(36):39088-39097.
Loss of the tumor suppressor gene AT-rich interactive domain-containing protein 1A (ARID1A) has been demonstrated in several cancers, but its prognostic role is unknown. We aimed to investigate the risk associated with loss of ARID1A (ARID1A−) for all-cause mortality, cancer-specific mortality and recurrence of disease in subjects with cancer. PubMed and SCOPUS search from database inception until 01/31/2015 without language restriction was conducted, contacting authors for unpublished data. Eligible were prospective studies reporting data on prognostic parameters in subjects with cancer, comparing participants with presence of ARID1A (ARID1A+) vs. ARID1A−, assessed either via immunohistochemistry (loss of expression) or with genetic testing (presence of mutation). Data were summarized using risk ratios (RR) for number of deaths/recurrences and hazard ratios (HR) for time-dependent risk related to ARID1A− adjusted for potential confounders. Of 136 hits, 25 studies with 5,651 participants (28 cohorts; ARID1A−: n = 1,701; ARID1A+: n = 3,950), with a mean follow-up period of 4.7 ± 1.8 years, were meta-analyzed. Compared to ARID1A+, ARID1A− significantly increased cancer-specific mortality (studies = 3; RR = 1.55, 95% confidence interval (CI) = 1.19–2.00, I2 = 31%). Using HRs adjusted for potential confounders, ARID1A− was associated with a greater risk of cancer-specific mortality (studies = 2; HR = 2.55, 95%CI = 1.19–5.45, I2 = 19%) and cancer recurrence (studies = 10; HR = 1.93, 95%CI = 1.22–3.05, I2 = 76%). On the basis of these results, we have demonstrated that loss of ARID1A shortened time to cancer-specific mortality, and to recurrence of cancer when adjusting for potential confounders. For its role, this gene should be considered as an important potential target for personalized medicine in cancer treatment.
PMCID: PMC4770758  PMID: 26384299
ARID1A; SWI/SNF; chromatin remodeling; targeted therapy; tumor suppressor gene
5.  The level of RECQL1 expression is a prognostic factor for epithelial ovarian cancer 
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.
PMCID: PMC4255635  PMID: 25424877
Ovarian cancer; RECQL1; siRNA; Apoptosis
6.  4-Methylumbelliferone inhibits ovarian cancer growth by suppressing thymidine phosphorylase expression 
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.
PMCID: PMC4198731  PMID: 25304388
4-Methylumbelliferone; Ovarian cancer; Peritonitis carcinomatosa; Hymidine phosphorylase; HRA cells
7.  The prophylactic effects of a traditional Japanese medicine, goshajinkigan, on paclitaxel-induced peripheral neuropathy and its mechanism of action 
Molecular Pain  2014;10:61.
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.
PMCID: PMC4176860  PMID: 25240613
Paclitaxel; Goshajinkigan; Peripheral neuropathy; Degeneration of the ganglion cells; TRPV4
8.  A phase I study of irinotecan and pegylated liposomal doxorubicin in recurrent ovarian cancer (Tohoku Gynecologic Cancer Unit 104 study) 
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.
PMCID: PMC4000409  PMID: 24585045
Recurrent ovarian cancer; Chemotherapy; CPT-11; PLD
9.  Inhibitory effects of aromatase inhibitor on estrogen receptor-alpha positive ovarian cancer in mice 
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.
PMCID: PMC3895704  PMID: 24410765
Recurrent ovarian cancer; Letrozole; Estrogen receptor alpha; Aromatase inhibitor; Anti-angiogenesis
10.  Decreased ARID1A expression is correlated with chemoresistance in epithelial ovarian cancer 
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.
PMCID: PMC3893676  PMID: 24459582
ARID1A; Chemoresistance; Epithelial ovarian cancer; Relapse
11.  Redistribution of resistance and sensitivity to platinum during the observation period following treatment of epithelial ovarian cancer 
Molecular and Clinical Oncology  2013;2(2):212-218.
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.
PMCID: PMC3917783  PMID: 24649335
relapsed epithelial ovarian cancer; platinum sensitivity; treatment-free interval; progression-free interval; histological type
12.  A Case of Small Cell Carcinoma of the Vagina 
Rare Tumors  2013;5(4):e58.
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.
PMCID: PMC3882930  PMID: 24416492
small cell carcinoma of the vagina; radiotherapy
13.  Loss of ARID1A expression is an early molecular event in tumor progression from ovarian endometriotic cyst to clear cell and endometrioid carcinoma 
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.
PMCID: PMC3460070  PMID: 22976498
14.  Recurrent epithelial ovarian cancer and hormone therapy 
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.
PMCID: PMC3845958  PMID: 24303498
Recurrent ovarian cancer; Hormone therapy; Letrozole; Anastrozole; Tamoxifen; Fulvestrant
15.  Comparison of the outcome between cervical adenocarcinoma and squamous cell carcinoma patients with adjuvant radiotherapy following radical surgery: SGSG/TGCU Intergroup Surveillance 
Molecular and Clinical Oncology  2013;1(4):780-784.
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.
PMCID: PMC3916196  PMID: 24649246
adenocarcinoma; squamous cell carcinoma; uterine cervix; radiotherapy
16.  Presentation of two patients with malignant granulosa cell tumors, with a review of the literature 
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.
PMCID: PMC3490972  PMID: 22963202
Ovarian malignant granulosa cell tumor; BEP combination therapy; Aromatase inhibitor
17.  Malignant Ovarian Tumors with Induced Expression of Carbonyl Reductase Show Spontaneous Regression 
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.
PMCID: PMC3290113  PMID: 22408375
apoptosis; carbonyl reductase; ovarian tumor; phagocytosis

Results 1-17 (17)