Canna starch improves immune functions and the intestinal environment in mice.

The present study was conducted to elucidate the dietary effects of canna starch on the immune functions and intestinal luminal environment in mice. The amylose and resistant starch characteristics were determined for six types of starch, including edible canna. Canna starch was found to be higher in amylose and resistant starch compared with the other starches. BALB/c mice were fed 3.16% (low-canna group) and 6.32% (high-canna group) canna starch for 2 weeks, and then intestinal parameters were measured. Fecal IgA and mucin levels were markedly elevated by canna starch intake. IgA levels in serum and spleen lymphocytes were elevated by canna starch intake in the high-canna group, but not in the low-canna group. When the mice were fed canna starch, the cecum weight increased, and the pH in the cecum decreased. The high-canna group had significantly increased levels of Clostridium subcluster XIVa lactic acid, acetic acid, and n-butyric acid in the cecum compared with the control group. These results suggested that canna starch supplementation changed the intestinal microbiota and enhanced the intestinal immune and barrier functions and cecal organic acids in mice.

Effects of maternal and fetal choline concentrations on the fetal growth and placental DNA methylation of 12 target genes related to fetal growth, adipogenesis, and energy metabolism.

AIM: We performed a birth cohort study involving 124 mother-infant pairs to investigate whether placental DNA methylation is associated with maternal choline status and fetal development. METHODS: Plasma choline concentration was assayed longitudinally in the 1st and 3rd trimesters and at term-pregnancy in mothers and cord blood. Placental DNA methylation was measured for 12 target candidate genes that are related to fetal growth, adipogenesis, lipid and energy metabolism, or long interspersed nuclear elements. RESULTS: Higher maternal plasma and cord blood choline levels at term tended to associate with lower birthweight (r = -0.246, P < 0.013; r = -0.290, P < 0.002) and body mass index (BMI) at birth (r = 0.344, P < 1E-3; r = -0.360, P < 1E-3). The correlation between maternal plasma choline level and cord blood choline level was relatively modest (r = 0.049, P = 0.639). There was an inverse correlation between placental DNA methylation at the retinoid X receptor alpha (RXRA) gene and maternal plasma choline level (r = -0.188 to r = -0.452, P = 0.043 to P < 1E-3 at three points). RXRA methylation level was positively associated with birthweight and BMI at birth (r = 0.306, P = 0.001; r = 0.390, P < 1E-3). Further, RXRA methylation was inversely correlated with RXRA gene expression level (r = 0.333, P < 1E-3). CONCLUSION: Our results suggest that the association between maternal choline status and placental RXRA methylation represents a potential fetal programing mechanism contributing to fetal growth.

The Emerging Role of FOXL2 in Regulating the Transcriptional Activation Function of Estrogen Receptor ß: An Insight Into Ovarian Folliculogenesis.

Germline mutations of the fork-head transcriptional factor forkhead box L2 (FOXL2) predispose embryos to autosomal-dominant blepharophimosis-ptosis-epicanthus inversus syndrome with primary ovarian insufficiency in female patients, but the mechanisms of FOXL2 in ovarian follicular development remain elusive. Estrogens produced by ovarian granulosa cells and estrogen receptor (ER) α and ERß play fundamental roles in ovarian pathophysiology, and a previous study revealed that ERα and ERß physically interact with FOXL2. However, the underlying functions of these interactions have not been investigated. Herein, we report an ERß-specific repressive function of FOXL2. Histological examination demonstrated that FOXL2 expression tends to be intense during early follicular development. Immunoprecipitation revealed that ERß and FOXL2 interact in a ligand-independent manner. In vitro pull-down assays revealed a direct interaction between FOXL2 and the activation function (AF)-1/2 domain of ERß. The expression of FOXL2 represses the ligand-dependent transcriptional activation of ERß, but FOXL2 does not influence the ligand-dependent transcriptional activation of ERα. Consistent with these results, RNA interference-mediated depletion of FOXL2 stimulates the expression of the ERß-downstream gene p450 aromatase. The convergence between FOXL2 functions and ERß-mediated transcription in the ovary suggests the putative mechanism of FOXL2 in early-phase follicular development, which may be partially attributed to the regulation of ERß-dependent gene expression.

Autophagy inhibition augments resveratrol-induced apoptosis in Ishikawa endometrial cancer cells.

Resveratrol (RSV), a polyphenolic compound derived from red wine, inhibits the proliferation of various types of cancer. RSV induces apoptosis in cancer cells, while enhancing autophagy. Autophagy promotes cancer cell growth by driving cellular metabolism, which may counteract the effect of RSV. The present study aimed to elucidate the correlation between RSV and autophagy and to examine whether autophagy inhibition may enhance the antitumor effect of RSV in endometrial cancer cells. Cell proliferation, cell cycle progression and apoptosis were examined, following RSV exposure, by performing MTT assays, flow cytometry and annexin V staining, respectively, in an Ishikawa endometrial cancer cell line. Autophagy was evaluated by measuring the expression levels of light chain 3, II (LC3-II; an autophagy marker) by western blotting and immunofluorescence. Chloroquine (CQ) and small interfering RNAs targeting autophagy related (ATG) gene 5 (ATG5) or 7 (ATG7) were used to inhibit autophagy, and the effects in combination with RSV were assessed using MTT assays. RSV treatment suppressed cell proliferation in a dose-dependent manner in Ishikawa cells. In addition, RSV exposure increased the abundance of the sub-G1 population and induced apoptosis. LC3-II accumulation was observed following RSV treatment, indicating that RSV induced autophagy. Combination treatment with CQ and RSV more robustly suppressed growth inhibition and apoptosis, compared with RSV treatment alone. Knocking down ATG5 or ATG7 expression significantly augmented RSV-induced apoptosis. The results of the present study indicated that RSV-induced autophagy may counteract the antitumor effect of RSV in Ishikawa cells. Combination treatment with RSV and an autophagy inhibitor, such as CQ, may be an attractive therapeutic option for treating certain endometrial cancer cells.

MDM2 is a potential therapeutic target and prognostic factor for ovarian clear cell carcinomas with wild type TP53.

MDM2, a ubiquitin ligase, suppresses wild type TP53 via proteasome-mediated degradation. We evaluated the prognostic and therapeutic value of MDM2 in ovarian clear cell carcinoma. MDM2 expression in ovarian cancer tissues was analyzed by microarray and real-time PCR, and its relationship with prognosis was evaluated by Kaplan-Meier method and log-rank test. The anti-tumor activities of MDM2 siRNA and the MDM2 inhibitor RG7112 were assessed by cell viability assay, western blotting, and flow cytometry. The anti-tumor effects of RG7112 in vivo were examined in a mouse xenograft model. MDM2 expression was significantly higher in clear cell carcinoma than in ovarian high-grade serous carcinoma (P = 0.0092) and normal tissues (P = 0.035). High MDM2 expression determined by microarray was significantly associated with poor progression-free survival and poor overall survival (P = 0.0002, and P = 0.0008, respectively). Notably, RG7112 significantly suppressed cell viability in clear cell carcinoma cell lines with wild type TP53. RG7112 also strongly induced apoptosis, increased TP53 phosphorylation, and stimulated expression of the proapoptotic protein PUMA. Similarly, siRNA knockdown of MDM2 induced apoptosis. Finally, RG7112 significantly reduced the tumor volume of xenografted RMG-I clear cell carcinoma cells (P = 0.033), and the density of microvessels (P = 0.011). Our results highlight the prognostic value of MDM2 expression in clear cell carcinoma. Thus, MDM2 inhibitors such as RG7112 may constitute a class of potential therapeutics.

Significance of survivin as a prognostic factor and a therapeutic target in endometrial cancer.

INTRODUCTION: Survivin is an anti-apoptotic protein encoded by the baculoviral inhibitor of apoptosis repeat-containing (BIRC5) gene and is upregulated in 83% of endometrial cancers. We aimed to elucidate the prognostic importance of BIRC5 expression, and evaluate survivin as a therapeutic target for endometrial cancer, by knock-down of BIRC5 and using the survivin inhibitor-YM155. METHODS: RNA sequencing data in 234 patients with endometrial carcinoma was obtained from The Cancer Genome Atlas database, and analyzed using Kaplan-Meier method, log-rank test and Cox proportional hazard model. Expressions of survivin in 16 endometrial cancer cell lines were analyzed by western blotting. Knocking down effect on survivin expression was evaluated using a small interfering RNA (siRNA). The anti-proliferative and pro-apoptotic effects of YM155 were assessed with cell viability, flow cytometry, and annexin V/propidium iodide assays. RESULTS: High expression of BIRC5 was associated with poor progression free survival (P=0.006), and shown to be an independent prognostic factor (HR=1.97, 95% CI=1.29-4.5, P=0.045). Survivin was upregulated in 14 of 16 (87.5%) endometrial cancer cell lines, compared with endometrial immortalized cells. Apoptosis was induced by knockdown of BIRC5 in all 3 cell lines examined. YM155 showed increased population of sub-G1 cells (P<0.001) in all 16 cell lines, and IC50 values to YM155 were <50nm in 15 cell lines. YM155 dose-dependently and significantly increased the apoptotic cell population in all 16 cell lines (P<0.001). CONCLUSIONS: Present study indicated that survivin expression is a significant prognostic factor and that survivin is a promising therapeutic target for endometrial cancer.

Synergistic antitumor effects of combination PI3K/mTOR and MEK inhibition (SAR245409 and pimasertib) in mucinous ovarian carcinoma cells by fluorescence resonance energy transfer imaging.

The aim of this study was to clarify the synergistic effects of dual inhibition of the PI3K/mTOR and MAPK pathways in ovarian mucinous carcinoma (OMC) cells, using fluorescence resonance energy transfer (FRET) imaging. We exposed 6 OMC cell lines to a PI3K/mTOR inhibitor (voxtalisib, SAR245409) and/or a MEK inhibitor (pimasertib), and evaluated synergistic effects using the Chou-Talalay method. Then, S6K (PI3K pathway) and ERK (MAPK pathway) kinase activities, and their individual proliferative or cytotoxic effects were calculated by time-lapse FRET imaging. In combination with SAR245409, pimasertib (30 nM) synergistically inhibited cell growth (combination indexes: 0.03-0.5) and induced apoptosis in all 6 OMC cell lines. FRET-imaging results demonstrated that ERK inhibition induced both anti-proliferation and apoptosis in a dose-dependent manner in both MCAS and OAW42 cells. However, S6K inhibition suppressed proliferation in a threshold manner in both cell lines, although apoptosis was only induced in OAW42 cells. These results demonstrated that combined PI3K/mTOR and MEK inhibition exhibited synergistic antitumor effects in OMC cells and that FRET imaging is useful for analyzing kinase activities in live cells and elucidating their cytostatic and cytotoxic effects.

Enhanced efficacy against cervical carcinomas through polymeric micelles physically incorporating the proteasome inhibitor MG132.

Treatment of recurrent or advanced cervical cancer is still limited, and new therapeutic choices are needed for improving prognosis and quality of life of patients. Because human papilloma virus (HPV) infection is critical in cervical carcinogenesis, with the E6 and E7 oncogenes of HPV degrading tumor suppressor proteins through the ubiquitin proteasome system, the inhibition of the ubiquitin proteasome system appears to be an ideal target to suppress the growth of cervical tumors. Herein, we focused on the ubiquitin proteasome inhibitor MG132 (carbobenzoxy-Leu-Leu-leucinal) as an anticancer agent against cervical cancer cells, and physically incorporated it into micellar nanomedicines for achieving selective delivery to solid tumors and improving its in vivo efficacy. These MG132-loaded polymeric micelles (MG132/m) showed strong tumor inhibitory in vivo effect against HPV-positive tumors from HeLa and CaSki cells, and even in HPV-negative tumors from C33A cells. Repeated injection of MG132/m showed no significant toxicity to mice under analysis by weight change or histopathology. Moreover, the tumors treated with MG132/m showed higher levels of tumor suppressing proteins, hScrib and p53, as well as apoptotic degree, than tumors treated with free MG132. This enhanced efficacy of MG132/m was attributed to their prolonged circulation in the bloodstream, which allowed their gradual extravasation and penetration within the tumor tissue, as determined by intravital microscopy. These results support the use of MG132 incorporated into polymeric micelles as a safe and effective therapeutic strategy against cervical tumors.

Continuous Glucose Monitoring in Patients with Abnormal Glucose Tolerance during Pregnancy: A Case Series.

Abnormal glucose tolerance during pregnancy is associated with perinatal complications. We used continuous glucose monitoring (CGM) in pregnant women with glucose intolerance to achieve better glycemic control and to evaluate the maternal glucose fluctuations. We also used CGM in women without glucose intolerance (the control cases). Furthermore, the standard deviation (SD) and mean amplitude of glycemic excursions (MAGE) were calculated for each case. For the control cases, the glucose levels were tightly controlled within a very narrow range; however, the SD and MAGE values in pregnant women with glucose intolerance were relativity high, suggesting postprandial hyperglycemia. Our results demonstrate that pregnant women with glucose intolerance exhibited greater glucose fluctuations compared with the control cases. The use of CGM may help to improve our understanding of glycemic patterns and may have beneficial effects on perinatal glycemic control, such as the detection of postprandial hyperglycemia in pregnant women.

Prognostic importance of CDK4/6-specific activity as a predictive marker for recurrence in patients with endometrial cancer, with or without adjuvant chemotherapy.

BACKGROUND: Pathologically low-risk endometrial cancer patients do not receive postoperative treatment; however, 10-15% of these patients show recurrence with poor prognosis. We evaluated the clinical importance of cyclin-dependent kinase 4/6 (CDK4/6) activity, and its significance as a novel biomarker for the prognosis and chemo-sensitivity of endometrioid endometrial carcinoma (EEC). METHODS: Cyclin-dependent kinase 4/6 expression and enzyme activity in 109 tumour samples from patients with EEC were examined with a cell-cycle profiling (C2P) assay. CDK4/6-specific activity (CDK4/6SA) was determined, and its relationship with clinicopathological factors and expression of Ki-67 was analysed. RESULTS: CDK4/6-specific activity was significantly correlated with Ki-67 (P=0.035), but not with any other clinicopathological characteristics. CDK4/6SA was significantly higher (P=0.002) in pathologically low-risk patients (not receiving adjuvant chemotherapy, n=74) than in intermediate- or high-risk patients (receiving adjuvant chemotherapy, n=35). In addition, patients with high CDK4/6SA (>3.0) showed significantly (P=0.024) shorter progression-free survival (PFS) than those with low CDK4/6SA (<3.0). Although Ki-67 expression itself was not a marker for prognosis, the combination of high CDK4/6SA and high Ki-67 expression (>15%) was robustly associated with shorter PFS (P=0.015), and this combination was an independent poor prognostic factor in the low-risk group. Inversely, in the intermediate-/high-risk group, patients with high CDK4/6SA had a tendency of a more favourable prognosis compared with patients with low CDK4/6SA (P=0.063). CONCLUSIONS: CDK4/6-specific activity can be used as a biomarker to predict prognosis and, possibly, chemo-sensitivity. The combination of Ki-67 expression might strengthen the clinical usefulness of CDK4/6SA as a biomarker.

Putative tumor suppression function of SIRT6 in endometrial cancer.

SIRT6, a member of the sirtuin family, has been identified as a candidate tumor suppressor. To pursue the role of SIRT6 in endometrial cancer, we investigated the anti-tumorigenic function of SIRT6. The expression of SIRT6 negatively affected the proliferation of AN3CA and KLE endometrial cancer cells. Increased expression of SIRT6 resulted in the induction of apoptosis by repressing the expression of the anti-apoptotic protein survivin. Consistent with this result, a survivin inhibitor YM155 efficiently inhibited cellular proliferation and induced apoptosis. These results revealed that SIRT6 might function as a tumor suppressor of endometrial cancer cells.

Antitumor activity of a combination of dual PI3K/mTOR inhibitor SAR245409 and selective MEK1/2 inhibitor pimasertib in endometrial carcinomas.

OBJECTIVE: We aimed to clarify whether dual inhibition of PI3K/MAPK and MAPK pathways synergistically suppresses cell growth in endometrial cancer cells. METHODS: We exposed a panel of 12 endometrial cancer cell lines to a PI3K/mTOR inhibitor (voxtalisib, SAR245409) and/or a MEK inhibitor (pimasertib). The effect of each drug singly or in combination was evaluated by MTT assay, flow cytometry, and immunoblotting. Combination indexes (CIs) were calculated using the Chou-Talalay method to evaluate the synergy. RESULTS: The IC50 values for SAR245409 and pimasertib varied from 0.5 µM to 7 µM and from 0.1 µM to >20 µM, respectively. A combination of both compounds (1 µM SAR245409 and 30 nM pimasertib) caused a synergistic antitumor effect in 6 out of 12 endometrial cell lines (CI, 0.07-0.46). The synergistic effect was exclusively observed in 6 pimasertib-sensitive cell lines (IC50 of pimasertib, ≤5 µM). We found that 30 nM pimasertib, a concentration much lower than the IC50 for each cell line, was sufficient to cause a synergistic effect with SAR245409. Flow cytometric analysis showed that this combination significantly increased the population of G1 cells. However, a combination of rapamycin (an mTOR inhibitor) and pimasertib did not induce a synergistic effect in endometrial cancer cells, except for HEC-1B cells. CONCLUSIONS: The combination of a PI3K/mTOR inhibitor and a MEK inhibitor induced a synergistic antitumor effect in certain endometrial cancer cells. This study underscores the importance of using optimized doses of antitumor agents, singly or in combination, in treating endometrial cancer.

Integrated copy number and expression analysis identifies profiles of whole-arm chromosomal alterations and subgroups with favorable outcome in ovarian clear cell carcinomas.

Ovarian clear cell carcinoma (CCC) is generally associated with chemoresistance and poor clinical outcome, even with early diagnosis; whereas high-grade serous carcinomas (SCs) and endometrioid carcinomas (ECs) are commonly chemosensitive at advanced stages. Although an integrated genomic analysis of SC has been performed, conclusive views on copy number and expression profiles for CCC are still limited. In this study, we performed single nucleotide polymorphism analysis with 57 epithelial ovarian cancers (31 CCCs, 14 SCs, and 12 ECs) and microarray expression analysis with 55 cancers (25 CCCs, 16 SCs, and 14 ECs). We then evaluated PIK3CA mutations and ARID1A expression in CCCs. SNP array analysis classified 13% of CCCs into a cluster with high frequency and focal range of copy number alterations (CNAs), significantly lower than for SCs (93%, P < 0.01) and ECs (50%, P = 0.017). The ratio of whole-arm to all CNAs was higher in CCCs (46.9%) than SCs (21.7%; P < 0.0001). SCs with loss of heterozygosity (LOH) of BRCA1 (85%) also had LOH of NF1 and TP53, and LOH of BRCA2 (62%) coexisted with LOH of RB1 and TP53. Microarray analysis classified CCCs into three clusters. One cluster (CCC-2, n = 10) showed more favorable prognosis than the CCC-1 and CCC-3 clusters (P = 0.041). Coexistent alterations of PIK3CA and ARID1A were more common in CCC-1 and CCC-3 (7/11, 64%) than in CCC-2 (0/10, 0%; P < 0.01). Being in cluster CCC-2 was an independent favorable prognostic factor in CCC. In conclusion, CCC was characterized by a high ratio of whole-arm CNAs; whereas CNAs in SC were mainly focal, but preferentially caused LOH of well-known tumor suppressor genes. As such, expression profiles might be useful for sub-classification of CCC, and might provide useful information on prognosis.

PI3K/mTOR pathway inhibition overcomes radioresistance via suppression of the HIF1-α/VEGF pathway in endometrial cancer.

Radiation therapy is a key therapeutic strategy for endometrial carcinomas. However, biomarkers that predict radiosensitivity and drugs to enhance this sensitivity have not yet been established. We aimed to investigate the roles of TP53 and MAPK/PI3K pathways in endometrial carcinomas and to identify appropriate radiosensitizing therapeutics. D10 values (the irradiating dose required to reduce a cell population by 90%) were determined in eight endometrial cancer cell lines with known mutational statuses for TP53, PIK3CA, and KRAS. Cells were exposed to ionizing radiation (2-6Gy) and either a dual PI3K/mTOR inhibitor (NVP-BEZ235) or a MEK inhibitor (UO126), and their radiosensitizing effects were evaluated using clonogenic assays. The effects of silencing hypoxia-inducible factor-1 α (HIF-1α) expression with small interfering RNAs (siRNAs) were evaluated following exposure to ionizing radiation (2-3Gy). D10 values ranged from 2.0 to 3.1Gy in three cell lines expressing wild-type TP53 or from 3.3 to more than 6.0Gy in five cell lines expressing mutant TP53. NVP-BEZ235, but not UO126, significantly improved radiosensitivity through the suppression of HIF-1α/vascular endothelial growth factor-A expression. HIF-1α silencing significantly increased the induction of the sub-G1 population by ionizing radiation. Our study data suggest that TP53 mutation and PI3K pathway activation enhances radioresistance in endometrial carcinomas and that targeting the PI3K/mTOR or HIF-1α pathways could improve radiosensitivity.

HPV-16 impairs the subcellular distribution and levels of expression of protein phosphatase 1γ in cervical malignancy.

BACKGROUND: The high risk Human Papillomavirus (HPV) E6 oncoproteins play an essential role in the development of cervical malignancy. Important cellular targets of E6 include p53 and the PDZ domain containing substrates such as hScrib and Dlg. We recently showed that hScrib activity was mediated in part through recruitment of protein phosphatase 1γ (PP1γ). METHODS: Expression patterns of hScrib and PP1γ were assessed by immunohistochemistry of HPV-16 positive cervical intraepithelial neoplasm (CIN), classified as CIN1 (n = 4), CIN2 (n = 8), CIN3 (n = 8), cervical carcinoma tissues (n = 11), and HPV-negative cervical tissues (n = 8), as well as by subfractionation assay of the HPV-16 positive cervical cancer cell lines, CaSki and SiHa. To explore the effects of the HPV-16 oncoproteins, we have performed siRNA knockdown of E6/E7 expression, and monitored the effects on the expression patterns of hScrib and PP1γ. RESULTS: We show that PP1γ levels in HPV-16 positive tumour cells are reduced in an E6/E7 dependent manner. Residual PP1γ in these cells is found mostly in the cytoplasm as opposed to the nucleus where it is predominantly found in normal cells. We have found a striking concordance with redistribution in the pattern of expression (9/11; 81.8%) and loss of PP1γ expression in HPV-16 positive cervical tumours (2/11; 18.2%). Furthermore, this loss of PP1γ expression and redistribution in the pattern of expression occurs progressively as the lesions develop (8/8; 100%). CONCLUSION: Together, these results suggest that PP1γ may be a novel target of the HPV-16 oncoproteins and indicate that it might be a potential novel biomarker for HPV-16 induced malignancy.

The anti-malarial chloroquine suppresses proliferation and overcomes cisplatin resistance of endometrial cancer cells via autophagy inhibition.

OBJECTIVE: The anti-malarial drug chloroquine (CQ) is also known as an autophagy inhibitor. Autophagy can promote tumor growth by fueling the necessary energy metabolism and inducing resistance to chemotherapy and/or irradiation in various human cancers. However, the role of autophagy in endometrial cancer has not yet been established. We investigated the anti-tumor effects and autophagy inhibition caused by CQ in endometrial cancer cells. METHODS: Cell proliferation and cell cycle were assessed in response to CQ in six endometrial cancer cell lines by using an MTT assay and/or flow cytometry. To assess the level of autophagy, western blotting and an immunofluorescence assay were used to measure LC3 expression. The effects of knockdown of either ATG5 or ATG7, both of which are indispensable for induction of autophagy, were assessed via an MTT assay. Sensitivity to CQ was compared between parental and cisplatin-resistant (CP-r) Ishikawa endometrial cancer cells. RESULTS: CQ suppressed proliferation in all six endometrial cancer cell lines in a dose-dependent manner, whereas it increased the population of apoptotic cells. Inhibition of autophagy via knockdown of either ATG5 or ATG7 decreased the sensitivity to CQ. Additionally, sensitivity to cisplatin was improved by knocking down ATG5 or ATG7. Finally, CP-r Ishikawa cells, with a high basal level of autophagy, were more sensitive to CQ than parental Ishikawa cells. CONCLUSIONS: Our data suggest that autophagy is involved in endometrial tumor growth and cisplatin resistance. Furthermore, our data support a therapeutic role for CQ in endometrial cancer cells with upregulation of autophagy.

SIRT3 positively regulates the expression of folliculogenesis- and luteinization-related genes and progesterone secretion by manipulating oxidative stress in human luteinized granulosa cells.

SIRT3 is a member of the sirtuin family and has recently emerged as a vital molecule in controlling the generation of reactive oxygen species (ROS) in oocytes. Appropriate levels of ROS play pivotal roles in human reproductive medicine. The aim of the present study was to investigate SIRT3 expression and analyze the SIRT3-mediated oxidative response in human luteinized granulosa cells (GCs). Human ovarian tissues were subjected to immunohistochemical analysis to localize SIRT3 expression. Hydrogen peroxide and human chorionic gonadotropin were used to analyze the relationship between ROS and SIRT3 by quantitative RT-PCR and Western blotting. Intracellular levels of ROS were investigated by fluorescence after small interfering RNA-mediated knockdown of SIRT3 in human GCs. To uncover the role of SIRT3 in folliculogenesis and luteinization, mRNA levels of related genes and the progesterone concentration were analyzed by quantitative RT-PCR and immunoassays, respectively. We detected the expression of SIRT3 in the GCs of the human ovary. The mRNA levels of SIRT3, catalase, and superoxide dismutase 1 were up-regulated by hydrogen peroxide in both COV434 cells and human GCs and down-regulated by human chorionic gonadotropin. Knockdown of SIRT3 markedly elevated ROS generation in human GCs. In addition, SIRT3 depletion resulted in decreased mRNA expression of aromatase, 17ß-hydroxysteroid dehydrogenase 1, steroidogenic acute regulatory protein, cholesterol side-chain cleavage enzyme, and 3ß-hydroxysteroid dehydrogenase in GCs and thus resulted in decreased progesterone secretion. These results have the important clinical implication that SIRT3 might play a positive role in the folliculogenesis and luteinization processes in GCs, possibly by sensing and regulating the generation of ROS. Activation of SIRT3 function might help to sustain human reproduction by maintaining GCs as well as oocytes.