Differences of Bone Mineral Density by Characteristics of Sports in Amenorrheic Athletes.

Hypothalamic amenorrhea leads to a hypoestrogenic state, causing decreased bone mineral density (BMD), while strong impact loading on bone has been shown to increase BMD. The purpose of this study is to compare BMD in female athletes based on menstrual status and their sports/events by impact loading characteristics. BMD at the lumbar spine was measured by dual-energy X-ray absorptiometry and hormone level. The subjects were classified into four groups and BMD and hormone levels were compared among the four groups, which were divided into amenorrheic athletes (AAs) and eumenorrheic athletes (EAs). This study recruited 410 female athletes (164 in the AAs and 246 in the EAs), 55 athletes in non-impact sports, 123 in low-impact sports, 141 in multidirectional sports, and 91 in high-impact sports. In the AAs group, BMD Z-score was lowest in low-impact sports (Z-score: -1.53 [-1.76, -1.30]), and was highest in high-impact sports (Z-score: 0.02 [-0.34, 0.38]). In multidirectional and high-impact sports, BMD Z-score in the AAs group did not show results lower than the average for non-athletes. When screening female athletes for low BMD, it is important to evaluate the risk of low BMD based on the impact loading characteristics of their sports/events, in addition to the menstrual state.

Development of University of Tokyo's eating disorders inventory in female athletes.

AIMS: This study aimed to develop a scale to screen for eating disorders in female athletes. METHODS: Preliminary survey: A total of 275 female athletes (mean age: 19.4 ± 1.0 years) and 7 female athletes diagnosed with eating disorders (mean age: 20.1 ± 2.5 years) were administered screening items prepared based on an existing scale, followed by exploratory factor analysis. Main survey: Six items, relating to three factors, were extracted, and 201 female athletes (mean age: 22.3 ± 4.8 years) and 6 female athletes diagnosed with current or a history of eating disorders (mean age: 18.8 ± 2.9 years) were queried. The diagnostic validity of the scale was then evaluated. RESULTS: Preliminary survey: Questions (α = 0.71) were extracted from six items, relating to three factors, and collectively termed the University of Tokyo's eating disorders inventory in female athletes (TEDIFA). To determine the scale cut-off score, ROC analysis was performed with the total score, and the cut-off and gray zone scores were set at 13 and 11, respectively. Main survey: At the cut-off score of 13, AUC, sensitivity, and specificity were 0.83 (p < 0.05), 75%, and 90%, respectively. CONCLUSIONS: The scale that was developed, TEDIFA, consisted of six items. The cut-off scores were set at 11 for the gray zone (sensitivity: 75%; specificity: 56%; accurate diagnosis rate: 60%), and 13 for positivity (sensitivity: 75%; specificity: 90%; accurate diagnosis rate: 87%), demonstrating the reliability and validity of the scale.

The oncogene KRAS promotes cancer cell dissemination by stabilizing spheroid formation via the MEK pathway.

BACKGROUND: Peritoneal dissemination is a critical prognostic factor in ovarian cancer. Although stabilized spheroid formation promotes cancer cell peritoneal dissemination in ovarian cancer, the associated oncogenes are unknown. In this study, we assessed the role of the KRAS oncogene in ovarian cancer cell dissemination, focusing on the stability of cells in spheroid condition, as well as the modulation of intracellular signaling following spheroid transformation. METHODS: We used ID8, a murine ovarian cancer cell line, and ID8-KRAS, an oncogenic KRAS (G12 V)-transduced ID8 cell line in this study. Spheroid-forming (3D) culture and cell proliferation assays were performed to evaluate the growth characteristics of these cells. cDNA microarray analysis was performed to identify genes involved in KRAS-associated signal transduction in floating condition. A MEK inhibitor was used to evaluate the effect on cancer peritoneal dissemination. RESULTS: Cell viability and proliferation in monolayer (2D) cultures did not differ between ID8 and ID8-KRAS cells. However, the proportions of viable and proliferating ID8-KRAS cells in 3D culture were approximately 2-fold and 5-fold higher than that of ID8, respectively. Spheroid-formation was increased in ID8-KRAS cells. Analysis of peritoneal floating cells obtained from mice intra-peritoneally injected with cancer cells revealed that the proportion of proliferating cancer cells was approximately 2-fold higher with ID8-KRAS than with ID8 cells. Comprehensive cDNA microarray analysis revealed that pathways related to cell proliferation, and cell cycle checkpoint and regulation were upregulated specifically in ID8-KRAS cells in 3D culture, and that some genes partially regulated by the MEK-ERK pathway were upregulated only in ID8-KRAS cells in 3D culture. Furthermore, a MEK inhibitor, trametinib, suppressed spheroid formation in 3D culture of ID8-KRAS cells, although trametinib did not affect 2D-culture cell proliferation. Finally, we demonstrated that trametinib dramatically improved the prognosis for mice with ID8-KRAS tumors in an in vivo mouse model. CONCLUSIONS: Our data indicated that KRAS promoted ovarian cancer dissemination by stabilizing spheroid formation and that the MEK pathway is important for stabilized spheroid formation. Disruption of spheroid formation by a MEK inhibitor could be a therapeutic target for cancer peritoneal dissemination.

Characterization of novel transcripts of human papillomavirus type 16 using cap analysis gene expression technology.

We have performed cap-analysis gene expression (CAGE) sequencing to identify the regulatory networks that orchestrate genome-wide transcription in human papillomavirus type 16 (HPV16)-positive cervical cell lines of different grades: W12E, SiHa, and CaSki. Additionally, a cervical intraepithelial neoplasia grade 1 (CIN1) lesion was assessed for identifying the transcriptome expression profile. Here we have precisely identified a novel antisense noncoding viral transcript in HPV16. In conclusion, CAGE sequencing should pave the way for understanding a diversity of viral transcript expression.

Expression of Par3 polarity protein correlates with poor prognosis in ovarian cancer.

BACKGROUND: Previous studies have shown that the cell polarity protein partitioning defective 3 (Par3) plays an essential role in the formation of tight junctions and definition of apical-basal polarity. Aberrant function of this protein has been reported to be involved in epithelial-mesenchymal transition (EMT) and cancer invasion. The aim of this study was to examine the functional mechanism of Par3 in ovarian cancer. METHODS: First, we investigated the association between Par3 expression level and survival of 50 ovarian cancer patients. Next, we conducted an in vitro analysis of ovarian cancer cell lines, focusing on the cell line JHOC5, to investigate Par3 function. To investigate the function of Par3 in invasion, the IL-6/STAT3 pathway was analyzed upon Par3 knockdown with siRNA. The effect of siRNA treatment was assessed by qPCR, ELISA, and western blotting. Invasiveness and cell proliferation following treatment with siRNA against Par3 were investigated using Matrigel chamber, wound healing, and cell proliferation assays. RESULTS: Expression array data for ovarian cancer patient samples revealed low Par3 expression was significantly associated with good prognosis. Univariate analysis of clinicopathological factors revealed significant association between high Par3 levels and peritoneal dissemination at the time of diagnosis. Knockdown of Par3 in JHOC5 cells suppressed cell invasiveness, migration, and cell proliferation with deregulation of IL-6/STAT3 activity. CONCLUSION: Taken together, these results suggest that Par3 expression is likely involved in ovarian cancer progression, especially in peritoneal metastasis. The underlying mechanism may be that Par3 modulates IL-6 /STAT3 signaling. Here, we propose that the expression of Par3 in ovarian cancer may control disease outcome.

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.

Differences in screening and treating relative energy deficiency in sport between the United States of America and Japan.

BACKGROUND: The diagnosis and treatment of relative energy deficiency in sport (RED-S) are challenging owing to variations in symptoms and the absence of specific guidelines. This study aimed to investigate differences in the diagnosis and follow-up of RED-S, its consequences, and related factors among sports medicine physicians with different backgrounds in Japan and the USA and examine the differences between the two countries. METHODS: An anonymous survey regarding the diagnosis and treatment processes of RED-S was distributed to sports medicine physicians via email. Respondents included 58 sports medicine physicians from the USA and 241 from Japan. RESULTS: The findings showed that 77.6% of the US physicians screened athletes for RED-S, whereas 17.5% of their Japanese counterparts did so. Moreover, 98.3% and 36.7% of the US and Japanese physicians, respectively, answered that they screened athletes for eating disorders upon suspicion of low energy availability. Logistic regression analysis revealed that the number of US sports medicine physicians who screened athletes for the female athlete triad (Triad) and RED-S (odds ratio [OR] = 12.78, P<0.001) and adhered to specific criteria for athlete suspension and return-to-play (OR=33.67, P<0.01) was higher than that of their Japanese counterparts. CONCLUSIONS: The prevalence of RED-S-related screening and treatment differed between US and Japanese sports medicine physicians. Educating sports medicine physicians about the diagnosis and treatment of athletes with possible signs of RED-S is important in treating female athletes and further investigations are required to identify why the physicians screened/not screened the athletes.

Age and menstrual cycle may be important in establishing pregnancy in female athletes after retirement from competition.

BACKGROUND: Although it has been shown that amenorrhea associated with low energy availability or relative energy deficiency in sport affects body physiology in female athletes, the association between menstrual dysfunction during active sports careers and reproductive function after retirement is not clear. OBJECTIVE: To investigate the association between menstrual dysfunction during their active sports career and post-retirement infertility in female athletes. METHODS: A voluntary web-based survey was aimed at former female athletes who had become pregnant and gave birth to their first child after retirement. Nine multiple-choice questions were included, on maternal age, competition levels and menstrual cycles during active sports careers, time from retirement to pregnancy, the time of resumption of spontaneous menstruation after retirement, conception method, and mode of delivery, etc. Regarding cases of primary and secondary amenorrhea among the abnormal menstrual cycle group, only those whose spontaneous menstruation had not recovered from retirement to the time of pregnancy were included in the study. The association between the presence of abnormal menstrual cycles from active sports careers to post-retirement pregnancy and the implementation of infertility treatment was evaluated. RESULTS: The study population included 613 female athletes who became pregnant and gave birth to their first child after retiring from competitive sports. Of the 613 former athletes, the infertility treatment rate was 11.9%. The rate of infertility treatment was significantly higher in athletes with abnormal than normal menstrual cycles (17.1% vs. 10.2%, p = 0.0225). Multivariable logistic regression analysis showed that maternal age (adjusted odds ratio [OR] 1.194; 95% confidence interval [CI] 1.129, 1.262) and abnormal menstrual cycles (OR and 1.903; adjusted OR 1.105, 3.278) were the relevant factors for infertility treatment. CONCLUSION: It was suggested that menstrual dysfunction that persist from active sports careers to post-retirement may be a factor in infertility when trying to conceive after retirement.

The Coprinopsis cinerea septin Cc.Cdc3 is involved in stipe cell elongation.

We have identified and characterized a Coprinopsis cinerea mutant defective in stipe elongation during fruiting body development. In the wild-type, stipe cells elongate at the maturation stage of fruiting, resulting in very slender cells. In the mutant, the stipe cells fail to elongate, but become rather globular at the maturation stage. We found that the mutant phenotype is rescued by a gene encoding a homolog of Saccharomyces cerevisiae CDC3 septin, Cc.Cdc3. The C. cinerea genome includes 6 septin genes, 5 of which, including Cc.cdc3, are highly transcribed during stipe elongation in the wild type. In the mutant, the level of Cc.cdc3 transcription in the stipe cells remains the same as that in the mycelium, and the level of Cc.cdc10 transcription is approximately 100 times lower than that in the wild-type stipe cells. No increase in transcription of Cc.cdc3 in the mutant may be due to the fact that the Cc.cdc3 gene has a 4-base pair insertion in its promoter and/or that the promoter region is methylated in the mutant. Overexpressed EGFP-Cc.Cdc3 fusion protein rescues the stipe elongation in the transformants, localizes to the cell cortex and assembles into abundant thin filaments in the elongating stipe cells. In contrast, in vegetative hyphae, EGFP-Cc.Cdc3 is localized to the hyphal tips of the apical cells of hyphae. Cellular defects in the mutant, combined with the localization of EGFP-Cc.Cdc3, suggest that septin filaments in the cell cortex provide the localized rigidity to the plasma membrane and allow cells to elongate cylindrically.

Live-cell imaging of septins and cell polarity proteins in the growing dikaryotic vegetative hypha of the model mushroom Coprinopsis cinerea.

The developmental biology underlying the morphogenesis of mushrooms remains poorly understood despite the essential role of fungi in the terrestrial environment and global carbon cycle. The mushroom Coprinopsis cinerea is a leading model system for the molecular and cellular basis of fungal morphogenesis. The dikaryotic vegetative hyphae of this fungus grow by tip growth with clamp cell formation, conjugate nuclear division, septation, subapical peg formation, and fusion of the clamp cell to the peg. Studying these processes provides many opportunities to gain insights into fungal cell morphogenesis. Here, we report the dynamics of five septins, as well as the regulators CcCla4, CcSpa2, and F-actin, visualized by tagging with fluorescent proteins, EGFP, PA-GFP or mCherry, in the growing dikaryotic vegetative hyphae. We also observed the nuclei using tagged Sumo proteins and histone H1. The five septins colocalized at the hyphal tip in the shape of a dome with a hole (DwH). CcSpa2-EGFP signals were observed in the hole, while CcCla4 signals were observed as the fluctuating dome at the hyphal tip. Before septation, CcCla4-EGFP was also occasionally recruited transiently around the future septum site. Fluorescent protein-tagged septins and F-actin together formed a contractile ring at the septum site. These distinct specialized growth machineries at different sites of dikaryotic vegetative hyphae provide a foundation to explore the differentiation program of various types of cells required for fruiting body formation.

Use of Cap Analysis Gene Expression to detect human papillomavirus promoter activity patterns at different disease stages.

Transcription of human papillomavirus (HPV) genes proceeds unidirectionally from multiple promoters. Direct profiling of transcription start sites (TSSs) by Cap Analysis Gene Expression (CAGE) is a powerful strategy for examining individual HPV promoter activity. The objective of this study was to evaluate alterations of viral promoter activity during infection using CAGE technology. We used CAGE-based sequencing of 46 primary cervical samples, and quantitatively evaluated TSS patterns in the HPV transcriptome at a single-nucleotide resolution. TSS patterns were classified into two types: early promoter-dominant type (Type A) and late promoter-dominant type (Type B). The Type B pattern was more frequently found in CIN1 and CIN2 lesions than in CIN3 and cancer samples. We detected transcriptomes from multiple HPV types in five samples. Interestingly, in each sample, the TSS patterns of both HPV types were the same. The viral gene expression pattern was determined by the differentiation status of the epithelial cells, regardless of HPV type. We performed unbiased analyses of TSSs across the HPV genome in clinical samples. Visualising TSS pattern dynamics, including TSS shifts, provides new insights into how HPV infection status relates to disease state.

Detachment from the primary site and suspension in ascites as the initial step in metabolic reprogramming and metastasis to the omentum in ovarian cancer.

Cancer cell metabolism is currently considered to be context dependent, and metabolic reprogramming is being widely investigated. It is known that ovarian cancer often metastasizes to the omentum. Given that the omentum itself contains a high concentration of adipocytes, ovarian cancer is thought to be a good model for research into metabolic reprogramming (particularly the shift to lipid metabolism). The present study investigated the switch to lipid metabolism in the metabolic reprogramming of ovarian cancer cells. The present study first considered the possibility of epigenetic involvement. Using an open database (GSE 85293 and GSE2109), the methylation status and gene expression patterns of the primary tumor site (ovary) and the metastatic tumor site (omentum) were compared. However, no evidence was obtained regarding the involvement of epigenetics (at least in terms of DNA methylation). The influence of suspension in ascites on metabolism was then considered, and a suspension culture was used as an in vitro model. It was demonstrated that ovarian cancer cells that are detached from the primary site and suspended in ascites have enhanced lipid metabolism. Additionally, it was demonstrated that these cells express high levels of the cancer stem cell (CSC) marker cluster of differentiation 44 and c-kit in a balanced manner as they approach the omentum. Accordingly, these cells activate the mammalian target of rapamycin pathway, which is thought to be advantageous for cancer cell metastasis. In conclusion, the present study proposed one explanation for why ovarian cancer cells are likely to disseminate to the peritoneal cavity, and in particular to the omentum.

Therapeutic significance of targeting survivin in cervical cancer and possibility of combination therapy with TRAIL.

Loss of p53 function due to human papillomavirus (HPV) infection induces resistance to apoptosis in cervical cancer cells. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which induces apoptosis in a p53-independent manner, may provide an alternative strategy for treating cervical cancer. Survivin, an antiapoptotic protein that is highly expressed in cancer cells, regulates apoptosis and the cell cycle. Here, we investigated the therapeutic potential of targeting survivin, while focusing on the TRAIL-induced apoptosis pathway. The viability and cell cycle of HPV16-positive CaSki and SiHa cells were assessed after survivin knockdown by small interfering RNA (si-survivin). E-cadherin expression was also assessed after si-survivin treatment, using western blotting. SiHa (a TRAIL-resistant cell line) was used for further studies. The small molecule YM155 and resveratrol (RVT; a polyphenol with the potential to suppress survivin expression) were used as survivin inhibitors. The effects of si-survivin and survivin inhibitors on TRAIL- or cisplatin (CDDP)-induced apoptosis were analyzed by annexin-V staining. si-survivin treatment decreased cell viability and led to G2/M arrest, accompanied by morphological changes and E-cadherin upregulation in both CaSki and SiHa cells. si-survivin and YM155 synergistically sensitized TRAIL-resistant SiHa cells to TRAIL-induced apoptosis (p < 0.05). However, si-survivin and YM155 only slightly increased CDDP-induced apoptosis. RVT markedly enhanced TRAIL-induced apoptosis by suppressing survivin expression. Targeting of survivin expression might be an ideal strategy for cervical cancer treatment as it would decrease viable cell number and enhance apoptosis sensitivity. Further, combination therapy with TRAIL, rather than CDDP, may be compatible with the proposed survivin-targeting strategy.

Intraperitoneal neutrophils activated by KRAS-induced ovarian cancer exert antitumor effects by modulating adaptive immunity.

Increased neutrophil counts are a hallmark of a poor prognosis for cancer. We previously reported that KRAS promoted tumorigenesis and increased neutrophil counts in a mouse peritoneal cancer model. In the current study, we evaluated the role of increased neutrophils in cancer progression, as well as their influence on the intraperitoneal microenvironment. A mouse peritoneal cancer model was established using the KRAS-transduced mouse ovarian cancer cell line, ID8-KRAS. Neutrophil function was assessed by neutrophil depletion in ID8-KRAS mice. Neutrophil depletion markedly accelerated tumor formation; this was accompanied by an increase in interleukin-6 concentrations in ascites. Neutrophil depletion significantly decreased the amount of local and systemic CD8+ T cells, while increasing the amount of local CD4+ T cells, accompanied by an increased amount of monocytic myeloid-derived suppressor cells (M-MDSCs) and regulatory T cells (Tregs) (P<0.05). The roles of peritoneal neutrophils (PENs) in CD8+ T cell activation were assessed in vitro. PENs of ID8-KRAS mice had a strong potential to enhance T cell proliferation with a higher expression of the T cell costimulatory molecules OX40 ligand (OX40L) and 4-1BB ligand (4-1BBL), as compared with peripheral blood neutrophils (PBNs). These findings suggest that neutrophils recruited into the KRAS-induced tumor microenvironment (TME) have antitumor properties with the potential to modulate the numbers of M-MDSCs and Tregs and activate CD8+ T cells through T cell costimulatory molecules.

Targeting glutamine metabolism and the focal adhesion kinase additively inhibits the mammalian target of the rapamycin pathway in spheroid cancer stem-like properties of ovarian clear cell carcinoma in vitro.

Ovarian cancer is one of the leading causes of death in the world, which is linked to its resistance to chemotherapy. Strategies to overcome chemoresistance have been keenly investigated. Culturing cancer cells in suspension, which results in formation of spheroids, is a more accurate reflection of clinical cancer behavior in vitro than conventional adherent cultures. By performing RNA-seq analysis, we found that the focal adhesion pathway was essential in spheroids. The phosphorylation of focal adhesion kinase (FAK) was increased in spheroids compared to adherent cells, and inhibition of FAK in spheroids resulted in inhibition of the downstream mammalian target of the rapamycin (mTOR) pathway in ovarian clear cell carcinomas. This result also suggested that only using a FAK inhibitor might have limitations because the phosphorylation level of FAK could not be reduced to the level in adherent cells, and it appeared that some combination therapies might be necessary. We previously reported that glutamine and glutamate concentrations were higher in spheroids than adherent cells, and we investigated a synergistic effect targeting glutamine metabolism with FAK inhibition on the mTOR pathway. The combination of AOA, a pan-transaminase inhibitor, and PF 573228, a FAK inhibitor, additively inhibited the mTOR pathway in spheroids from ovarian clear cell carcinomas. Our in vitro study proposed a rationale for the positive and negative effects of using FAK inhibitors in ovarian clear cell carcinomas and suggested that targeting glutamine metabolism could overcome the limitation of FAK inhibitors by additively inhibiting the mTOR pathway.

Intracellular signaling entropy can be a biomarker for predicting the development of cervical intraepithelial neoplasia.

While the mortality rates for cervical cancer have been drastically reduced after the introduction of the Pap smear test, it still is one of the leading causes of death in women worldwide. Additionally, studies that appropriately evaluate the risk of developing cervical lesions are needed. Therefore, we investigated whether intracellular signaling entropy, which is measured with microarray data, could be useful for predicting the risks of developing cervical lesions. We used three datasets, GSE63514 (histology), GSE27678 (cytology) and GSE75132 (cytology, a prospective study). From the data in GSE63514, the entropy rate was significantly increased with disease progression (normal < cervical intraepithelial neoplasia, CIN < cancer) (Kruskal-Wallis test, p < 0.0001). From the data in GSE27678, similar results (normal < low-grade squamous intraepithelial lesions, LSILs < high-grade squamous intraepithelial lesions, HSILs ≤ cancer) were obtained (Kruskal-Wallis test, p < 0.001). From the data in GSE75132, the entropy rate tended to be higher in the HPV-persistent groups than the HPV-negative group. The group that was destined to progress to CIN 3 or higher had a tendency to have a higher entropy rate than the HPV16-positive without progression group. In conclusion, signaling entropy was suggested to be different for different lesion statuses and could be a useful biomarker for predicting the development of cervical intraepithelial neoplasia.

Regeneration of cervical reserve cell-like cells from human induced pluripotent stem cells (iPSCs): A new approach to finding targets for cervical cancer stem cell treatment.

Cervical reserve cells are epithelial progenitor cells that are pathologically evident as the origin of cervical cancer. Thus, investigating the characteristics of cervical reserve cells could yield insight into the features of cervical cancer stem cells (CSCs). In this study, we established a method for the regeneration of cervical reserve cell-like properties from human induced pluripotent stem cells (iPSCs) and named these cells induced reserve cell-like cells (iRCs). Approximately 70% of iRCs were positive for the reserve cell markers p63, CK5 and CK8. iRCs also expressed the SC junction markers CK7, AGR2, CD63, MMP7 and GDA. While iRCs expressed neither ERα nor ERß, they expressed CA125. These data indicated that iRCs possessed characteristics of cervical epithelial progenitor cells. iRCs secreted higher levels of several inflammatory cytokines such as macrophage migration inhibitory factor (MIF), soluble intercellular adhesion molecule 1 (sICAM-1) and C-X-C motif ligand 10 (CXCL-10) compared with normal cervical epithelial cells. iRCs also expressed human leukocyte antigen-G (HLA-G), which is an important cell-surface antigen for immune tolerance and carcinogenesis. Together with the fact that cervical CSCs can originate from reserve cells, our data suggested that iRCs were potent immune modulators that might favor cervical cancer cell survival. In conclusion, by generating reserve cell-like properties from iPSCs, we provide a new approach that may yield new insight into cervical cancer stem cells and help find new oncogenic targets.

Low uptake of fluorodeoxyglucose in positron emission tomography/computed tomography in ovarian clear cell carcinoma may reflect glutaminolysis of its cancer stem cell-like properties.

The characteristics of ovarian cancers that showed low activation of glycolysis were investigated. Using medical records of patients with ovarian cancers who had undergone fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) prior to their primary surgery at the University of Tokyo Hospital between 2010 and 2015, we identified cases with a low uptake of FDG in PET/CT. We considered the maximum standardized uptake value (SUVmax) as the degree of glucose uptake. We investigated the properties which may account for the low activation of glycolysis in vitro. The expression level of alanine, serine, cysteine-preferring transporter 2 (ASCT2, a glutamine influx transporter), system L-type amino acid transporter 1 (LAT1, a glutamine efflux transporter) and glucose transporter 1 (GLUT1, a glucose influx transporter) were investigated by western blotting. The phosphorylation level of AMP-activated protein kinase (AMPK), which is one of the metabolic sensors, was also investigated. Most of the cases with a low uptake SUVmax were limited to patients with ovarian clear cell carcinoma (CCC). We obtained cancer stem cell (CSC)-like properties from CCC cell lines, and compared the expression levels of transporters between non-CSCs and CSCs. Whereas the expression level of ASCT2 was nearly unchanged between non-CSCs and CSCs, the expression levels of LAT1 and GLUT1 were decreased in CSCs compared to non-CSCs. The phosphorylation level of AMPK was reduced in CSCs compared to non-CSCs. In conclusion, we suggested that ovarian CCC showed low activation of glycolysis, and this may reflect glutaminolysis of its CSC-like properties.

Clinical significance of Gremlin 1 in cervical cancer and its effects on cancer stem cell maintenance.

Gremlin 1 is one of the bone morphogenetic protein (BMP) antagonists and is also related to differentiation in combination with BMPs and is associated with various types of diseases. Gremlin 1 is overexpressed in various types of human cancers and has been reported to play a role in cervical cancer oncogenesis. However, there is no report concerning the relationship between Gremlin 1 and cervical cancer stem cells (CSCs). The objective of the present study was to identify the clinical significance of Gremlin 1 in cervical cancer and its effects on CSC-like properties in vitro. Clinical samples were obtained. Gremlin 1 mRNA expression levels in the cervical cancer tissues were measured by RT-qPCR and assessed for correlation with their clinical prognosis [overall survival (OS), progression-free survival (PFS)] and with other prognostic factors. In vitro, cervical cancer, CaSki cells, exposed to Gremlin 1 (1,000 ng/ml) for 24 h were evaluated for expression of undifferentiated-cell markers (Nanog, Oct3/4, Sox2) by RT-qPCR, the population of ALDH-positive cells by flow cytometry and sphere-forming ability on a ultra-low attachment culture dish. Cervical cancer tissues from 104 patients were collected. A high mRNA expression level of Gremlin 1 was an independent poor prognostic factor of PFS but not of OS. A high mRNA expression level of Gremlin 1 was correlated with bulky (>4 cm) tumors. The Nanog mRNA expression level was significantly increased in the CaSki cells exposed to Gremlin 1 (P=0.0008) but not Oct3/4 and Sox2 mRNA expression levels. The population of ALDH-positive cells in the Gremlin 1-exposed cells was 1.41-fold higher compared with the control (P=0.0184). Sphere-forming ability was increased when 1,000 Gremlin 1-exposed cells were seeded (P=0.0379). In cervical cancer, it is suggested that Gremlin 1 may have a role in clinical recurrence and maintaining CSC-like properties.

Inhibition of endoplasmic reticulum (ER) stress sensors sensitizes cancer stem-like cells to ER stress-mediated apoptosis.

Although cancer stem cells (CSC) have been implicated in the development of resistance to anti-cancer therapy including chemotherapy, the mechanisms underlying chemo-resistance by CSC have not yet been elucidated. We herein isolated sphere-forming (cancer stem-like) cells from the cervical cancer cell line, SiHa, and examined the unfolded protein reaction (UPR) to chemotherapeutic-induced endoplasmic reticulum (ER) stress. We revealed that tunicamycin-induced ER stress-mediated apoptosis occurred in monolayer, but not sphere-forming cells. Biochemical assays demonstrated that sphere-forming cells were shifted to pro-survival signaling through the inactivation of IRE1 (XBP-1 splicing) and activation of PERK (elF2α phosphorylation) branches under tunicamycin-induced ER stress conditions. The proportion of apoptotic cells among sphere-forming cells was markedly increased by the tunicamycin+PERK inhibitor (PERKi) treatment, indicating that PERKi sensitized sphere-forming cells to tunicamycin-induced apoptosis. Cisplatin is also known to induce ER stress-mediated apoptosis. A low concentration of cisplatin failed to shift sphere-forming cells to apoptosis, although IRE1 branch, but not PERK, was activated. ER stress-mediated apoptosis occurred in sphere-forming cells by the cisplatin+IRE1α inhibitor (IRE1i) treatment. IRE1i, synergistic with cisplatin, up-regulated elF2α phosphorylation, and this was followed by the induction of CHOP in sphere-forming cells. The results of the present study demonstrated that the inhibition of ER stress sensors, combined with ER stress-inducible chemotherapy, shifted cancer stem-like cells to ER stress-mediated apoptosis.