PLAC8 promotes the autophagic activity and improves the growth priority of human trophoblast cells.

Autophagy plays an important role in the normal development and function of trophoblast cells and is precisely regulated during pregnancy. Dysregulated autophagy contributes to the abnormal proliferation of trophoblasts, which is closely related to the occurrence of pregnancy-related diseases. Placenta specific 8 (PLAC8, Onzin) is a multifaceted protein proven to promote autophagy and potentiate various tumor progression. Its role in trophoblasts remains elusive. In our present study, PLAC8 expression was detected in tissues of first-trimester placentas (n = 5), term placentas (n = 5), choriocarcinoma (n = 5), and placental site trophoblastic tumor (n = 5). PLAC8 expression was increased in gestational neoplasms compared with normal pregnancies. mCherry-EGFP-LC3B reporter and transmission electron microscopy confirmed PLAC8 promoted the autophagic flux of human trophoblast cells. Both gain-of-function and loss-of-function experiments demonstrated PLAC8-regulated autophagy-related genes, including ATG5, ATG12, and Beclin-1. In addition, our data showed that PLAC8 co-localized with p53 and promoted its degradation, and p53 re-expression partially abrogated the PLAC8-induced autophagy activity. Furthermore, the overexpression of PLAC8 promoted cell viability and proliferation, acting as a protective mechanism of trophoblasts against the cytotoxicity of etoposide (VP-16). Such a phenomenon was effectively abrogated by autophagy inhibitors 3-methyladenine (3-MA) and chloroquine (CQ). In conclusion, PLAC8-induced autophagy to promote the proliferation of trophoblasts. This study provided insights into the mechanism of PLAC8-induced autophagy in trophoblasts, which is significant for a wide range of gestational diseases and may contribute to developing novel treatment strategies for trophoblastic diseases.

lnc003875/miR-363/EGR1 regulatory network in the carcinoma -associated fibroblasts controls the angiogenesis of human placental site trophoblastic tumor (PSTT).

The rare gestational trophoblastic neoplasia placental site trophoblastic tumor (PSTT) frequently demonstrates a high degree of vascularization, which may facilitate the tumor metastasis. However, the underlying mechanisms remain largely unknown. In the present study, we found that early growth response 1 (EGR1) was highly expressed in the carcinoma-associated fibroblasts (CAFs) of PSTT tissues. Further data showed that miR-363 down-regulated EGR1 expression whereas long non-coding RNA NONHSAT003875 (lnc003875) up-regulated EGR1 expression in PSTT derived CAFs. lnc003875 exerted no effect on miR-363 expression, but it recovered the decrease of EGR1 caused by miR-363 mimic. The conditioned media from PSTT CAFs treated with miR-363 mimic abrogated the tube formation capacity of human umbilical vein endothelial cells (HUVECs), which can be partially restored by lnc003875 over-expression. Moreover, over-expression of EGR1 promoted the secretion of Angiopoietin-1 (Ang-1) in PSTT derived CAFs and improved the tube formation of HUVECs, which could be effectively abrogated by Ang-1 siRNAs. In vivo vasculogenesis assay demonstrated that lnc003875/EGR1 in PSTT derived CAFs promoted the vasculogenesis of HUVECs in C57BL/6 mice. Collectively, these findings indicated that lnc003875/miR-363/EGR1/Ang-1 in CAFs may be crucial for the angiogenesis of PSTT.

SMYD3 promotes implant metastasis of ovarian cancer via H3K4 trimethylation of integrin promoters.

Detachment of cancer cells from the primary tumor and formation of spheroids in ascites is required for implantation metastasis in epithelial ovarian cancer (EOC), but the underlying mechanism of this process has not been thoroughly elucidated. To mimic this process, ovarian cancer cells were grown in 3D and 2D culture. Hey and OVCA433 spheroids exhibited decreased cell proliferation and enhanced adhesion and invasion. SMYD3 expression was elevated in ovarian carcinoma spheroids in association with increased H3K4 methylation. Depletion of SMYD3 by transient siRNA, stable shRNA knockdown and the SMYD3 inhibitor BCI-121 all decreased spheroid invasion and adhesion. Gene expression arrays revealed downregulation of integrin family members. Inhibition assays confirmed that invasion and adhesion of spheroids are mediated by ITGB6 and ITGAM. SMYD3-deficient cells regained the ability to invade and adhere after forced overexpression of SMYD3, ITGB6 and ITGAM. However, this biological ability was not restored by forced overexpression of SMYD3 in ITGB6- and/or ITGAM-deficient cancer cells. SMYD3 and H3K4me3 binding at the ITGB6 and ITGAM promoters was increased in spheroids compared to that in monolayer cells, and the binding was decreased when SMYD3 expression was inhibited, consistent with the expression changes in integrins. SMYD3 expression and integrin-mediated adhesion were also activated in an intraperitoneal xenograft model and in EOC patient spheroids. In vivo, SMYD3 knockdown inhibited tumor metastasis and reduced ascites volume in both the intraperitoneal xenograft model and a PDX model. Overall, our results suggest that the SMYD3-H3K4me3-integrin pathway plays a crucial role in ovarian cancer metastasis to the peritoneal surface.

ß-catenin/LIN28B promotes the proliferation of human choriocarcinoma cells via Let-7a repression.

Choriocarcinoma is a rare and malignant trophoblastic tumor. However, the molecular mechanisms by which choriocarcinoma is regulated remain unknown. In the present study, we first elucidated that LIN28B was highly expressed in human choriocarcinoma tissues and choriocarcinoma cell lines. Our data further demonstrated that knockdown of LIN28B by small interfering RNA caused an increase in Let-7a expression in JAR cells. In addition, silencing of LIN28B inhibited IGF2BP1 expression and suppressed cell proliferation capacity, both of which can be markedly restored by Let-7a inhibitor. In contrast, LIN28B over-expression-improved cell proliferation was inhibited by Let-7a mimic. Knockdown of ß-catenin resulted in reduced expression of LIN28B and increased expression of Let-7a. Knockdown of ß-catenin also caused a decrease in cell proliferation, which can be recovered by re-expression of LIN28B or by Let-7a inhibitor. Collectively, our data indicate that ß-catenin/LIN28B/Let-7a pathway may be crucial for the regulation of cell proliferation in human choriocarcinoma cells.

APOBEC3B up-regulation independently predicts ovarian cancer prognosis: a cohort study.

BACKGROUND: Ovarian cancer is a heterogeneous disease with a high degree of genomic instability, pro-/antitumor immunity and inflammation, and remains the most lethal gynecologic cancer worldwide. APOBEC3B, a member of the AID/APOBEC family, is part of the innate immune system which plays a key role in combating exogenous infection especially viral infection. Studies have shown that APOBEC3B expression is elevated in a variety of cancer tissues and cell lines, and plays a prominent role in the genesis and evolution of various cancers. However, the clinical relevance of APOBEC3B in ovarian cancer needs to be further investigated. The current study aimed to evaluate the predictive value of APOBEC3B in ovarian cancer clinical outcome, and to explore possible molecular mechanisms contributing to ovarian cancer progression. METHODS: The expression of APOBEC3B in biopsy tissue specimens from 88 ovarian cancer patients was examined using immunohistochemistry. In addition, ovarian cancer cell lines were transfected with APOBEC3B siRNA or pLenti-APOBEC3B construct. Western blotting and SRB assay were performed to explore the role of APOBEC3B in ovarian cancer. RESULTS: Patients were followed for a median of 74.77 months following the time of surgery. Forty-two patients had died, 5 had relapsed but were still alive at the end of study, and 41 patients remained alive and had no recurrence. Over-expression of APOBEC3B was associated with advanced FIGO stage and elevated CA125 (both p< 0.05). Univariate analysis result showed that histological subtype, FIGO stage, intravascular tumor thrombus, CA125 and APOBEC3B expression were associated with overall survival and disease-free survival of ovarian cancer patients. Multivariate analysis result showed that higher APOBEC3B expression were an independent prognostic factor to predict both worse overall survival (hazard ratio: 5.18, 95% confidence interval: 1.40-11.95, p= 0.003) and disease-free survival (hazard ratio: 4.23, 95% confidence interval: 1.60-11.17, p= 0.004) of ovarian cancer patients. Furthermore, knockdown of APOBEC3B expression in ovarian cancer cells caused an decrease in cell line viability. CONCLUSIONS: APOBEC3B expression is an independent prognostic factor in ovarian cancer patients. Knockdown of APOBEC3B expression affects ovarian cancer viability.

ATM may be a protective factor in endometrial carcinogenesis with the progesterone pathway.

The purpose of the study was to explore the role and mechanism of ataxia-telangiectasia mutated (ATM) protein in endometrial carcinogenesis. A reverse-phase protein array (RPPA) was used to analyze the expression of ATM signal pathway proteins in Ishikawa and progesterone-insensitive Ishikawa. ATM expression was detected in endometrium specimens by immunohistochemistry, including 8 cases with proliferative endometrium, 6 cases with secretory endometrium, 10 cases with simple hyperplasia (SH), 13 cases of complex hyperplasia (CH), 11 cases of endometrial atypical hyperplasia (EAH), and 83 cases with type I endometrial cancer. The relationship between ATM expression and other clinicopathological indicators was also examined in type I endometrial cancer patients. The mechanisms of ATM were explored in vitro with the endometrial cell lines Ishikawa and RL95-2. A cell counting kit-8 (CCK-8) test and Western blot analysis were performed to test proliferation and protein expression. Statistical analysis was performed with SPSS19.0. The significance level was set at 0.05. ATM was increased with medroxyprogesterone acetate (MPA) stimulation in Ishikawa in RPPA. ATM expression gradually decreased in endometrial hyperplasic lesions compared with the normal proliferative and secretory endometrium and was the lowest in type I endometrial cancer. ATM expression was negatively correlated with pathological grades in type I endometrial cancer. In vitro, ATM silencing retarded proliferation inhibition in Ishikawa and RL95-2 treated with MPA. ATM silencing could down-regulate the MPA-stimulated signal proteins, including Chk2, P53, and caspase-3 in vitro. MPA might exert its role through activating the ATM-associated pathway, ATM-Chk2-P53-caspase-3 (active), preserving normal endometrium and protecting it from malignancies. ATM might be a promising indicator for endometrial hyperplasia and cancer.

Prognostic indicators in WHO 2003 low-grade endometrial stromal sarcoma.

AIMS: Endometrial stromal sarcoma (ESS) has traditionally been divided into low and high grade, but the World Health Organization (WHO, 2003) has changed the definition. Since 2003, many studies have used the old criteria, and few have focused on WHO 2003-defined ESS low grade (ESS-LG). The aim of this study was to investigate prognosticators in ESS-LG. METHODS AND RESULTS: We reviewed the WHO 2003 diagnostic criteria in 91 tumours (previously classified as ESS low and high grade). There were 68 cases of ESS-LG and 23 of undifferentiated endometrial sarcoma (UES). In the ESS-LG cases, the prognostic value of clinicopathological variables was studied. With a median follow-up of 79 months (range: 20-474 months), the recurrence and death rates were 5/68 (7%) and 1/68 (1.5%) in the ESS-LG cases. Ovarian preservation or no ovarian preservation (P < 0.0001, hazard ratio (HR) 10.4) and mitotic activity index (MAI) (0-3 versus >3, P = 0.005, HR 8.6) had independent prognostic value. Other frequently used MAI thresholds - age, tumour diameter, and vessel invasion - were not prognostic. Among patients without ovarian preservation (n = 61), none of 53 with MAI 0-3 suffered recurrence, contrasting with two of eight (25%) of those with MAI >3 (P = 0.003); one of these two recurrence patients died (P = 0.02). Among patients with ovarian preservation (n = 7), three (43%) suffered recurrence but none died, and MAI had no additional prognostic value. CONCLUSIONS: In ESS-LG, ovarian preservation and MAI >3 are associated with increased risk of recurrence.

Corilagin inhibits hepatocellular carcinoma cell proliferation by inducing G2/M phase arrest.

Hepatocellular carcinoma (HCC) is one of most common types of malignant tumours. Therefore, it is very important to identify powerful drugs and their antitumour mechanisms. Corilagin has a significant antitumour potential and lower toxicity in normal cells in vitro. The IC50 values of corilagin for normal Chang-liver cells and the HCC cell lines Bel7402 and SMMC7721 were 131.4, 24.5 and 23.4 µM, respectively, in the methyl thiazolyl tetrazolium (MTT) assay. MHCC97-H xenografts in Balb/c mice intraperitoneally injected with 30 mg/kg corilagin for 5 weeks showed a 47.3% inhibition of tumour growth in vivo. Furthermore, data from flow cytometry and Western blot analyses of cell cycle and cell cycle-related proteins suggest that corilagin arrests SMMC7721 cells at the G2/M phase by downregulating p-Akt and cyclin B1/cdc2 and upregulating p-p53 and p21(Cip1) . In conclusion, corilagin is a potential antitumour drug that is effective in retarding the growth of HCC, which is correlated with the activation of p-p53-p21(Cip1) -cdc2/cyclin B1.

A potential anti-tumor herbal medicine, Corilagin, inhibits ovarian cancer cell growth through blocking the TGF-ß signaling pathways.

BACKGROUND: Phyllanthus niruri L. is a well-known hepatoprotective and antiviral medicinal herb. Recently, we identified Corilagin as a major active component with anti-tumor activity in this herbal medicine. Corilagin is a member of the tannin family that has been discovered in many medicinal plants and has been used as an anti-inflammatory agent. However, there have been few reports of the anti-tumor effects of Corilagin, and its anti-tumor mechanism has not been investigated clearly. The aim of the present study is to investigate the anticancer properties of Corilagin in ovarian cancer cells. METHODS: The ovarian cancer cell lines SKOv3ip, Hey and HO-8910PM were treated with Corilagin and analyzed by Sulforhodamine B (SRB) cell proliferation assay, flow cytometry, and reverse phase protein array (RPPA). Corilagin was delivered intraperitoneally to mice bearing SKOv3ip xenografts. RESULTS: Corilagin inhibited the growth of the ovarian cancer cell lines SKOv3ip and Hey, with IC50 values of less than 30 µM, while displaying low toxicity against normal ovarian surface epithelium cells, with IC50 values of approximately 160 µM. Corilagin induced cell cycle arrest at the G2/M stage and enhanced apoptosis in ovarian cancer cells. Immunoblotting assays demonstrated that Cyclin B1, Myt1, Phospho-cdc2 and Phospho-Weel were down-regulated after Corilagin treatment. Xenograft tumor growth was significantly lower in the Corilagin-treated group compared with the untreated control group (P <0.05). More interestingly, Corilagin inhibited TGF-ß secretion into the culture supernatant of all tested ovarian cancer cell lines and blocked the TGF-ß-induced stabilization of Snail. In contrast, a reduction of TGF-ß secretion was not observed in cancer cells treated with the cytotoxic drug Paclitaxel, suggesting that Corilagin specifically targets TGF-ß secretion. Corilagin blocked the activation of both the canonical Smad and non-canonical ERK/AKT pathways. CONCLUSIONS: Corilagin extracted from Phyllanthus niruri L. acts as a natural, effective therapeutic agent against the growth of ovarian cancer cells via targeted action against the TGF-ß/AKT/ERK/Smad signaling pathways.

The temporal and spatial pattern evolution of provincial industrial carbon intensity under the carbon neutral target: evidence from China.

Industry is a core area to achieve the carbon neutrality target for most developing countries including China. Hence, it is of great practical significance to study the spatio-temporal characteristics of China's industrial carbon intensity and its evolution. The exploratory spatial data analysis methods were adopted to conduct global and local spatial correlation analysis in this paper. The result shows that (1) the industrial carbon emission intensity decreases year by year, with high industrial carbon emission intensity in the West and low in the East. (2) There is a correlation in the spatial distribution of industrial carbon intensity, with the Moran index experiencing the stage of descending first and then ascending. (3) The local spatial clustering of industrial carbon intensity is obvious. (4) Half of the provinces have experienced a leap, with the majority located in the western part of China. Based on these findings, it is concluded that industrial emission reduction policy synergy between provinces is particularly important, such as low-carbon industrial production policy and green industry development policy.

Transformation of epithelial ovarian cancer stemlike cells into mesenchymal lineage via EMT results in cellular heterogeneity and supports tumor engraftment.

Ovarian cancers are heterogeneous and contain stemlike cells that are able to self-renew and are responsible for sustained tumor growth. Metastasis in the peritoneal cavity occurs more frequently in ovarian cancer than in other malignancies, but the underlying mechanism remains largely unknown. We have identified that ovarian cancer stemlike cells (CSCs), which were defined as side population (SP) cells, were present in patients' ascitic fluid and mesenchymally transformed cell lines, ES-2 and HO-8910PM. SP cells, which were sorted from both cell lines and implanted into immunocompromised mice, were localized to the xenografted tumor boundary. In addition, SP cells exhibited an epithelial phenotype and showed a distinct gene expression profile with reduced expression of cell adhesion molecules (CAMs), indicating that SP cells exert an important role in ovarian cancer progression on the basis of their delicate interaction with the surrounding microenvironment and anatomical localization in tumors. In contrast, non-SP cells exhibited a more mesenchymal phenotype and showed more increased invasive potential than SP cells. This heterogeneity was observed as an endogenous transformation via the epithelial-mesenchymal transition (EMT) process. Inhibition of the EMT process by Snail1 silencing reduced the SP cell frequency, and affected their invasive capacity and engraftment. These findings illustrate the interplay between epithelial ovarian CSCs and the EMT, and exert a link to explain tumor heterogeneity and its necessity for ovarian cancer maintenance, metastasis and progression.

Methylation of HIN-1, RASSF1A, RIL and CDH13 in breast cancer is associated with clinical characteristics, but only RASSF1A methylation is associated with outcome.

BACKGROUND: Aberrant promoter CpG island hypermethylation is associated with transcriptional silencing. Tumor suppressor genes are the key targets of hypermethylation in breast cancer and therefore may lead to malignancy by deregulation of cell growth and division. Our previous pilot study with pairs of malignant and normal breast tissues identified correlated methylation of two pairs of genes - HIN-1/RASSFIA and RIL/CDH13 - with expression of estrogen receptors (ER), progesterone receptors (PR), and HER2 (HER2). To determine the impact of methylation on clinical outcome, we have conducted a larger study with breast cancers for which time to first recurrence and overall survival are known. METHODS: Tumors from 193 patients with early stage breast cancer who received no adjuvant systemic therapy were used to analyze methylation levels of RIL, HIN-1, RASSF1A and CDH13 genes for associations with known predictive and prognostic factors and for impact on time to first recurrence and overall survival. RESULTS: In this study, we found that ER was associated with RASSF1A methylation (p < 0.001) and HIN-1 methylation (p = 0.002). PR was associated with RIL methylation (p = 0.012), HIN-1 (p = 0.002), and RASSF1A methylation (p = 0.019). Tumor size was associated with RIL and CDH13 methylation (both p = 0.002), and S-phase was associated with RIL methylation (p = 0.036). Only RASSF1A was associated with worse time to first recurrence (p = 0.045) and worse overall survival (p = 0.016) after adjusting for age, tumor size, S-phase, estrogen receptor and progesterone receptor. CONCLUSIONS: Methylation of HIN-1, RASSF1A, RIL and CDH13 in breast cancers was associated with clinical characteristics, but only RASSF1A methylation was associated with time to first recurrence and overall survival. Our data suggest that RASSF1A methylation could be a potential prognostic biomarker.

Oestrogen receptor α mediates 17ß-estradiol enhancement of ovarian cancer cell motility through up-regulation of survivin expression.

OBJECTIVE: To determine the role of oestrogen receptor α (ERα) in the regulation of survivin expression by 17ß-estradiol (E(2)) in ovarian cancer cells and to evaluate the mechanism of E(2) action on ovarian cancer cell migration. METHODS: We performed RT-PCR and Western blot analysis to assess the expression of ERα in the ovarian cancer cell lines NIH:OVCAR-3 and SKOV-3. Full-length ERα cDNA was reintroduced into SKOV-3 cells through stable transfection. After treatment with E(2), with or without pre-incubation of anti-oestrogen compound ICI 182780, RT-PCR and Western blot analysis were performed to detect survivin expression at the mRNA and protein levels. RNA interference (RNAi) was used to inhibit the expression of survivin in SKOV-3 cells. Wound healing-induced migration and Matrigel invasion experiments were performed to determine the motility of ovarian cancer cells. RT-PCR and gelatin zymography were used to detect the expression and activity of MMP-9 in SKOV-3 cells. RESULTS: A stably transfected clone with over-expression of ERα, SKOV-α, was isolated. Exogenous or endogenous expression of ERα in SKOV-3 or NIH:OVCAR-3 cells resulted in a significant up-regulation of survivin in the presence of E(2). Pre-treatment with ICI 182780 attenuated the up-regulation of survivin by E(2). Previous data from our laboratory showed that E(2) enhanced the motility of ovarian cancer cells. RNAi strongly inhibited survivin expression in SKOV-3 cells. Knock-down of survivin expression reduced the migration and invasion of SKOV-3 cells, which correlated with down-regulation of MMP9 mRNA expression and activity. CONCLUSIONS: ERα may be responsible for the up-regulation of survivin after E(2) treatment in ovarian cancer cells. The mechanism of oestrogen-promoted ovarian cancer metastasis may due to the up-regulation of survivin conducted through the ERα signalling pathway.

Inhibiting the PI3K/Akt pathway reversed progestin resistance in endometrial cancer.

Progestin resistance is the main obstacle to successful conservative therapy in young endometrial cancer patients. To investigate the molecular events that lead to progestin resistance and to find a possible way to reverse progestin resistance in endometrial cancer, we established a progestin-resistant Ishikawa cell line by long-term progestin treatment to downregulate progesterone receptor (PR) expression. Both medoxyprogesterone acetate (MPA) and LY294002, a phosphatidylinositol 3-kinase (PI3K) inhibitor, were assayed for their effects on the proliferation of progestin-sensitive and progestin-resistant cancer cells, respectively. The MPA inhibited the PI3K/Akt pathway and suppressed cell proliferation in progestin-sensitive Ishikawa cells, but activated the PI3K/Akt pathway and had no effect on cell proliferation in progestin-resistant Ishikawa cells or HEC-1A cells. Inhibiting the PI3K/Akt pathway by LY294002 upregulated PR expression and diminished cell growth, especially in progestin-resistant endometrial cancer cells. In vivo endometrial cancer xenograft studies in nude mice also showed that inhibiting the PI3K/Akt pathway reversed progestin resistance in endometrial cancer. Our results indicate that activation of the PI3K/Akt pathway by progestin without PR mediation plays an important role in progestin resistance to endometrial cancer cells. In addition, inhibiting the PI3K/Akt pathway might reverse progestin resistance in endometrial cancer.

Decitabine and suberoylanilide hydroxamic acid (SAHA) inhibit growth of ovarian cancer cell lines and xenografts while inducing expression of imprinted tumor suppressor genes, apoptosis, G2/M arrest, and autophagy.

BACKGROUND: Epigenetic therapy has had a significant impact on the management of hematologic malignancies, but its role in the treatment of ovarian cancer remains to be defined. The authors previously demonstrated that treatment of ovarian and breast cancer cells with DNA methyltransferase and histone deacetylase (HDAC) inhibitors can up-regulate the expression of imprinted tumor suppressors. In this study, demethylating agents and HDAC inhibitors were tested for their ability to induce re-expression of tumor suppressor genes, inhibiting growth of ovarian cancer cells in culture and in xenografts. METHODS: Ovarian cancer cells (Hey and SKOv3) were treated with demethylating agents (5-aza-20-deoxycytidine [DAC] or 5-azacitidine [AZA]) or with HDAC inhibitors (suberoylanilide hydroxamicacid [SAHA] or trichostatin A [TSA]) to determine their impact on cellular proliferation, cell cycle regulation, apoptosis, autophagy, and re-expression of 2 growth inhibitory imprinted tumor suppressor genes: guanosine triphosphate-binding Di-RAS-like 3 (ARHI) and paternally expressed 3 (PEG3). The in vivo activities of DAC and SAHA were assessed in a Hey xenograft model. RESULTS: The combination of DAC and SAHA produced synergistic inhibition of Hey and SKOv3 cell growth by apoptosis and cell cycle arrest. DAC induced autophagy in Hey cells that was enhanced by SAHA. Treatment with both agents induced re-expression of ARHI and PEG3 in cultured cells and in xenografts, correlating with growth inhibition. Knockdown of ARHI decreased DAC-induced autophagy. DAC and SAHA inhibited the growth of Hey xenografts and induced autophagy in vivo. CONCLUSIONS: A combination of DAC and SAHA inhibited ovarian cancer growth while inducing apoptosis, G2/M arrest, autophagy, and re-expression of imprinted tumor suppressor genes.

The tumor suppressor gene ARHI regulates autophagy and tumor dormancy in human ovarian cancer cells.

The role of autophagy in oncogenesis remains ambiguous, and mechanisms that induce autophagy and regulate its outcome in human cancers are poorly understood. The maternally imprinted Ras-related tumor suppressor gene aplasia Ras homolog member I (ARHI; also known as DIRAS3) is downregulated in more than 60% of ovarian cancers, and here we show that re-expression of ARHI in multiple human ovarian cancer cell lines induces autophagy by blocking PI3K signaling and inhibiting mammalian target of rapamycin (mTOR), upregulating ATG4, and colocalizing with cleaved microtubule-associated protein light chain 3 (LC3) in autophagosomes. Furthermore, ARHI is required for spontaneous and rapamycin-induced autophagy in normal and malignant cells. Although ARHI re-expression led to autophagic cell death when SKOv3 ovarian cancer cells were grown in culture, it enabled the cells to remain dormant when they were grown in mice as xenografts. When ARHI levels were reduced in dormant cells, xenografts grew rapidly. However, inhibition of ARHI-induced autophagy with chloroquine dramatically reduced regrowth of xenografted tumors upon reduction of ARHI levels, suggesting that autophagy contributed to the survival of dormant cells. Further analysis revealed that autophagic cell death was reduced when cultured human ovarian cancer cells in which ARHI had been re-expressed were treated with growth factors (IGF-1, M-CSF), angiogenic factors (VEGF, IL-8), and matrix proteins found in xenografts. Thus, ARHI can induce autophagic cell death, but can also promote tumor dormancy in the presence of factors that promote survival in the cancer microenvironment.

Re-expression of ARHI (DIRAS3) induces autophagy in breast cancer cells and enhances the inhibitory effect of paclitaxel.

BACKGROUND: ARHI is a Ras-related imprinted gene that inhibits cancer cell growth and motility. ARHI is downregulated in the majority of breast cancers, and loss of its expression is associated with its progression from ductal carcinoma in situ (DCIS) to invasive disease. In ovarian cancer, re-expression of ARHI induces autophagy and leads to autophagic death in cell culture; however, ARHI re-expression enables ovarian cancer cells to remain dormant when they are grown in mice as xenografts. The purpose of this study is to examine whether ARHI induces autophagy in breast cancer cells and to evaluate the effects of ARHI gene re-expression in combination with paclitaxel. METHODS: Re-expression of ARHI was achieved by transfection, by treatment with trichostatin A (TSA) or by a combination of TSA and 5-aza-2'-deoxycytidine (DAC) in breast cancer cell cultures and by liposomal delivery of ARHI in breast tumor xenografts. RESULTS: ARHI re-expression induces autophagy in breast cancer cells, and ARHI is essential for the induction of autophagy. When ARHI was re-expressed in breast cancer cells treated with paclitaxel, the growth inhibitory effect of paclitaxel was enhanced in both the cell culture and the xenografts. Although paclitaxel alone did not induce autophagy in breast cancer cells, it enhanced ARHI-induced autophagy. Conversely, ARHI re-expression promoted paclitaxel-induced apoptosis and G2/M cell cycle arrest. CONCLUSIONS: ARHI re-expression induces autophagic cell death in breast cancer cells and enhances the inhibitory effects of paclitaxel by promoting autophagy, apoptosis, and G2/M cell cycle arrest.

Metformin reverses progestin resistance in endometrial cancer cells by downregulating GloI expression.

INTRODUCTION: A long-term treatment with progestin commonly results in progestin resistance in endometrial cancer. So, the aim of this study was to investigate the role of glyoxalase I (GloI), a mediator of chemotherapy resistance, in metformin reversal of progestin resistance in endometrial carcinoma. METHODS: The proliferation variety of endometrial cancer cells was determined by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-Diphenyltetrazolium (MTT) assay after exposure to medroxyprogesterone acetate, metformin, or both reagents; apoptosis rates were assessed by flow cytometry. Real-time polymerase chain reaction was used to evaluate the effect of small interfering RNA sequence on target gene expression. Western immunoblotting was performed to determine the expression of GloI and the molecules of the mammalian target of rapamycin (mTOR) pathway. RESULT: Knocking down GloI sensitized progestin-resistant Ishikawa cells to progestin. Metformin downregulated GloI expression, reversed progestin resistance, enhanced progestin-induced cell proliferation inhibition, and induced apoptosis in progestin-resistant Ishikawa cells. In addition, medroxyprogesterone acetate-induced mTOR phosphorylation was blocked by metformin. Metformin abolishes mTOR phosphorylation and inhibits GloI expression, attenuating proliferation and inducing apoptosis in progestin-resistant Ishikawa cells. CONCLUSIONS: Dysregulation of GloI expression in endometrial cancer may be part of the molecular mechanisms for progestin resistance.

The climate change vulnerability of China: spatial evolution and driving factors.

To cope with climate change, it is of great importance to describe the temporal and spatial evolution of climate change vulnerability and its driving factors. Therefore, this paper establishes a comprehensive index of vulnerability to climate change based on the vulnerability scoring diagram (VSD) framework. Moran's I index is used to study the spatial evolution characteristics of vulnerability, and spatial regression analysis is used to explore the factors influencing the spatial distribution of vulnerability. The results show that (1) the climate change vulnerability of China has decreased over time, and the sensitivity state is relatively stable; however, the annual change in exposure and adaptive capacity is significant. (2) The western region of China is more vulnerable than the eastern region, and the most vulnerable provinces are Guizhou and Gansu. (3) The regional vulnerability is generally in a significant spatial agglomeration state. (4) Finally, the driving factors of the spatial distribution of climate change vulnerability include forest coverage, the urban-rural income gap and information technology. These recommendations provide detailed discussions and scientific information for mitigating global warming and formulating long-term emission reduction targets, thereby optimizing resource allocation and providing spatial governance directions for the formulation of adaptation policies.

Snail is critical for tumor growth and metastasis of ovarian carcinoma.

Snail, a key inducer of epithelial-mesenchymal transition (EMT), plays an important role in cancer metastasis. To better understand the role of Snail in the metastasis of ovarian carcinoma, expression of Snail was knocked down by antisense-Snail in the highly metastatic ovarian cancer cell line HO8910PM. Gene array analysis revealed that blocking Snail expression suppressed the activity of matrix metalloproteinases (MMPs) and upregulated TIMP3, an MMP inhibitor. These findings suggest that Snail interacts with MMP during tumor invasion and metastasis. In addition, we examined the role of Snail in an ovarian cancer orthotopic model by using the antisense-Snail HO8910PM cell line. We found that the size of primary ovarian cancer tumor and the number of metastatic lesions were significantly reduced when Snail was knocked down. Confirming our initial findings, the activity of MMP2 was greatly inhibited in tumors from antisense-Snail cells. Furthermore, immunohistochemical analysis on ovarian cancer progression tissue array demonstrated that the expression of Snail was significantly higher in metastatic lesions, and Snail expression correlated with the stage of ovarian cancer. Interestingly, in early-stage tumors, Snail was localized in both the cytoplasm and nucleus. In late stage and metastatic lesions, the level of Snail was elevated, and Snail was localized to the nucleus. The expression level and nuclear localization of Snail were also inversely correlated with E-cadherin expression. Overall, our study indicates that Snail plays a critical role in tumor growth and metastasis of ovarian carcinoma through regulation of MMP activity.