Inhibition of AXL enhances chemosensitivity of human ovarian cancer cells to cisplatin via decreasing glycolysis.

Anexelekto (AXL), a member of the TYRO3-AXL-MER (TAM) family of receptor tyrosine kinases (RTK), is overexpressed in varieties of tumor tissues and promotes tumor development by regulating cell proliferation, migration and invasion. In this study, we investigated the role of AXL in regulating glycolysis in human ovarian cancer (OvCa) cells. We showed that the expression of AXL mRNA and protein was significantly higher in OvCa tissue than that in normal ovarian epithelial tissue. In human OvCa cell lines suppression of AXL significantly inhibited cell proliferation, and increased the sensitivity of OvCa cells to cisplatin, which also proved by nude mice tumor formation experiment. KEGG analysis showed that AXL was significantly enriched in the glycolysis pathways of cancer. Changes in AXL expression in OvCa cells affect tumor glycolysis. We demonstrated that the promotion effect of AXL on glycolysis was mediated by phosphorylating the M2 isoform of pyruvate kinase (PKM2) at Y105. AXL expression was significantly higher in cisplatin-resistant OvCa cells A2780/DDP compared with the parental A2780 cells. Inhibition of AXL decreased the level of glycolysis in A2780/DDP cells, and increased the cytotoxicity of cisplatin against A2780/DDP cells, suggesting that AXL-mediated glycolysis was associated with cisplatin resistance in OvCa. In conclusion, this study demonstrates for the first time that AXL is involved in the regulation of the Warburg effect. Our results not only highlight the clinical value of targeting AXL, but also provide theoretical basis for the combination of AXL inhibitor and cisplatin in the treatment of OvCa.

circCELSR1 facilitates ovarian cancer proliferation and metastasis by sponging miR-598 to activate BRD4 signals.

BACKGROUND: Ovarian cancer is one of the most common gynecologic cancers and has high mortality rate due to the lack of early diagnosis method and efficient therapeutic agents. circCELSR1 is up-regulated in ovarian cancer, but its role and mechanisms in ovarian cancer are unclear. METHODS: Gene expression of circCELSR1, miR-598 and BRD4 in ovarian cells was examined by qRT-PCR. Protein level was determined by Western blotting. Bioinformatic analysis and luciferase assay determined the molecular binding among circCELSR1, miR-598 and BRD4 3' UTR. Cell proliferation, migration, invasion and apoptosis were determined by colony formation, wound healing assay, transwell assay and flow cytometry analysis, respectively. An abdominal cavity metastasis nude mice model was used to determine the in vivo function of circCELSR1. RESULTS: circCELSR1 and BRD4 were promoted, but miR-598 was suppressed in various ovarian cancer cells. circCELSR1 bound to miR-598 and promoted expression of its downstream target BRD4. Knockdown of circCELSR1 suppressed proliferation, migration, invasion and epithelial-mesenchymal transition (EMT), but promoted apoptosis in ovarian cancer cells, and these effects were reversed by miR-598 inhibition or BRD4 overexpression. circCELSR1 inhibition decreased the expression of BRD4 and its downstream proliferation/migration related genes by targeting miR-598. Furthermore, knockdown of circCELSR1 suppressed ovarian cancer growth and metastasis in nude mice. CONCLUSION: Knockdown of circCELSR1 inhibited BRD4-mediated proliferation/migration related signaling via sponging miR-598, thereby repressing ovarian cancer progression. This study provides a new regulatory mechanism of ovarian cancer may facilitate the development of therapeutic agents for ovarian cancer.

lncRNA ABHD11-AS1, regulated by the EGFR pathway, contributes to the ovarian cancer tumorigenesis by epigenetically suppressing TIMP2.

OBJECTIVE: Epithelial ovarian cancer (EOC) is a common gynecologic malignancy characterized by extensive peritoneal metastasis and high mortality rate. ABHD11 Antisense RNA1 (ABHD11-AS1) has recently been identified as a regulator of growth and metastasis in multiple tumors, including EOC. However, the biological function and potential mechanism of ABHD11-AS1 in EOC remains poorly understood. METHODS: Immunohistochemistry, western blot, and qRT-PCR analysis were used to determine the expression pattern of ABHD11-AS1 and epidermal growth factor receptor (EGFR) in both EOC tissues and cell lines, respectively. Colony formation, transwell and wound healing assays were performed to evaluate the roles of EGFR and ABHD11-AS1 on the capacity of cell proliferation, migration, and invasion. Western blot analysis was performed to measure the regulation of EGFR pathway on STAT3. Moreover, chromatin immunoprecipitation was employed to demonstrate the interaction between ABHD11-AS1 and STAT3. RNA immunoprecipitation was subjected to prove the direct binding between ABHD11-AS1 and EZH2. Immunofluorescence staining was performed to measure the expression and localization of TIMP2. EOC mouse model was conducted for validating the role of ABHD11-AS1 in vivo. RESULTS: EGFR and ABHD11-AS1 were highly expressed in EOC tissues and cell lines. Knockdown of EGFR or ABHD11-AS1 inhibited cell growth, migration, and invasion of EOC cells. Expression of ABHD11-AS1 was regulated by the activation of EGFR signaling pathway, mediated by STAT3. Besides, ABHD11-AS1 was shown to silence TIMP2 by binding to chromatin-modifying enzyme EZH2. Furthermore, inhibition of EGFR pathway or ABHD11-AS1 repressed the tumor growth of EOC. CONCLUSION: We defined the regulatory relationship between the EGFR signaling pathway, ABHD11-AS1, EZH2, and TIMP2 suggesting that ABHD11-AS1 may act as an oncogene and a potential target for antitumor therapies in ovarian cancer.

KRAS: A Promising Therapeutic Target for Cancer Treatment.

Kirsten rat sarcoma 2 viral oncogene homolog (KRAS) is the most commonly mutated oncogene in human cancer. The developments of many cancers depend on sustained expression and signaling of KRAS, which makes KRAS a high-priority therapeutic target. Scientists have not successfully developed drugs that target KRAS, although efforts have been made last three decades. In this review, we highlight the emerging experimental strategies of impairing KRAS membrane localization and the direct targeting of KRAS. We also conclude the combinatorial therapies and RNA interference technology for the treatment of KRAS mutant cancers. Moreover, the virtual screening approach to discover novel KRAS inhibitors and synthetic lethality interactors of KRAS are discussed in detail.

M2-like tumor-associated macrophages-secreted EGF promotes epithelial ovarian cancer metastasis via activating EGFR-ERK signaling and suppressing lncRNA LIMT expression.

Background: Ovarian cancer (OC) is the gynecologic malignant tumor with high mortality. Accumulating evidence indicates that M2-like tumor-associated macrophages (TAMs) can secret EGF to participate in ovarian cancer growth, migration, and metastasis. An EGF-downregulated lncRNA, LIMT (lncRNA inhibiting metastasis), was identified as a critical regulator of mammary cell migration and invasion. Nevertheless, whether EGF secreted from M2-like TAMs regulates LIMT expression in ovarian cancer progression remains largely unknown. Methods: The human OC cell lines OV90 and OVCA429 were recruited in this study. The differentiation of the human monocyte cell line THP-1 into M2-like TAMs was confirmed using flow cytometry within the application of phorbol 12-myristate 13-acetate (PMA). ELISA was performed to detect EGF concentration in co-culture system of M2-like TAMs and OC cell lines. Moreover, CCK-8, flow cytometry and immunofluorescence staining of Ki67 were performed to assess the capacity of cell proliferation. Besides, cell migration and invasion were determined by wound healing and transwell assays. Furthermore, the expression levels of epithelial-mesenchymal transition (EMT) markers and EGFR/ERK signals were analyzed by qRT-PCR and western blot. Female athymic nude mice (8-12 weeks of age; n = 8 for each group) were recruited for in vivo study. Results: In the present study, THP-1 cells exhibited the phenotype markers of M2-like TAMs with low proportion of CD14+ marker and high proportion of CD68+, CD204+, CD206+ markers within the application of PMA. After co-culturing with M2-like TAMs, EGF concentration in the supernatants was significantly increased in a time-dependent manner. Besides, OC cells presented better cell viability, higher cell proliferation, and stronger migration and invasion. The expression of EMT-related markers N-cadherin, Vimentin and EGFR/ERK signals were markedly up-regulated, while E-cadherin was significantly decreased. However, these effects induced by co-culture system were reversed by the application of AG1478 (an EGFR inhibitor) or LIMT overexpression. Furthermore, the endogenous expression of LIMT was decreased in OC cell lines compared with the control group. Also, the in vivo experiments verified that the inhibition of EGFR signaling by AG1478 or overexpression of LIMT effectively repressed the tumor growth. Conclusion: Taken together, we demonstrated that EGF secreted by M2-like TAMs might suppress LIMT expression via activating EGFR-ERK signaling pathway to promote the progression of OC.

MiR-217 Inhibits M2-Like Macrophage Polarization by Suppressing Secretion of Interleukin-6 in Ovarian Cancer.

Ovarian cancer is one of the most deadly cancers with rapid proliferation and poor prognosis among patients. Therapies focusing on regulation of tumor immunity and microenvironments are developing. MiR-217 was dysregulated in cancer progress and plays important roles in tumorigenesis and metastasis. However, the role of miR-217 in regulation of macrophage polarization and its underlying molecular mechanism remain unclear. The expression of miR-217 in ovarian cancerous tissues and cell lines were assessed by qRT-PCR. And we detected the staining of CD86 and CD206 via flow-cytometry and the levels of Arg-1 and CCR2 by western-blot in order to evaluate M2 macrophage polarization. The targeting regulation of miR-217 on pro-inflammatory factor IL-6 was assessed by dual-luciferase reporter assay and western-blot. ELISA assay was used to evaluate the secretion of IL-6 and IL-10 of cells. MiR-217 was found to be downregulated in ovarian cancerous tissues and cell lines. This downregulation correlated with an increased expression of the IL-6, Arg-1, CCR2, and CD206 gene. The overexpression of miR-217 in SKOV3 cells can inhibit the polarization of macrophages towards an M2-like phenotype. We also found that IL-6 was validated to induce M2 macrophage polarization and its secretion in SKOV-3 cells was inhibited by miR-217 directly. Moreover, we revealed that miR-217 suppressed M2 macrophage polarization partly thought JAK/STAT3 signal pathway. Taken together, these findings indicate that miR-217 inhibits tumor-induced M2 macrophage polarization through targeting of IL-6 and regulation JAK3/STAT3 signaling pathway, which may provide a potential therapeutic target for treating ovarian cancer.

Identification of a Novel Bcl-2 Inhibitor by Ligand-Based Screening and Investigation of Its Anti-cancer Effect on Human Breast Cancer Cells.

Bcl-2 family protein is an important factor in regulating apoptosis and is associated with cancer. The anti-apoptotic proteins of Bcl-2 family, such as Bcl-2, are overexpression in numerous tumors, and contribute to cancer formation, development, and therapy resistance. Therefore, Bcl-2 is a promising target for drug development, and several Bcl-2 inhibitors are currently undergoing clinical trials. In this study, we carried out a QSAR-based virtual screening approach to develop potential Bcl-2 inhibitors from the SPECS database. Surface plasmon resonance (SPR) binding assay was performed to examine the interaction between Bcl-2 protein and the screened inhibitors. After that, we measured the anti-tumor activities of the 8 candidate compounds, and found that compound M1 has significant cytotoxic effect on breast cancer cells. We further proved that compound M1 downregulated Bcl-2 expression and activated apoptosis by inducing mitochondrial dysfunction. In conclusion, we identified a novel Bcl-2 inhibitor by QSAR screening, which exerted significant cytotoxic activity in breast cancer cells through inducing mitochondria-mediated apoptosis.

Tubeimoside-1, a triterpenoid saponin, induces cytoprotective autophagy in human breast cancer cells in vitro via Akt-mediated pathway.

Autophagy, a form of cellular self-digestion by lysosome, is associated with various disease processes including cancers, and modulating autophagy has shown promise in the treatment of various malignancies. A number of natural products display strong antitumor activity, yet their mechanisms of action remain unclear. To gain a better understanding of how traditional Chinese medicine agents exert antitumor effects, we screened 480 natural compounds for their effects on autophagy using a high content screening assay detecting GFP-LC3 puncta in HeLa cells. Tubeimoside-1 (TBMS1), a triterpenoid saponin extracted from Bolbostemma paniculatum (Maxim) Franquet (Cucurbitaceae), was identified as a potent activator of autophagy. The activation of autophagy by TBMS1 was evidenced by increased LC3-II amount and GFP-LC3 dots, observation of autophagosomes under electron microscopy, and enhanced autophagic flux. To explore the mechanisms underlying TBMS1-activated autophagy, we performed cheminformatic analyses and surface plasmon resonance (SPR) binding assay that showed a higher likelihood of the binding between Akt protein and TBMS1. In three human breast cancer cell lines, we demonstrated that Akt-mTOR-eEF-2K pathway was involved in TBMS1-induced activation of autophagy, while Akt-mediated downregulations of Mcl-1, Bcl-xl, and Bcl-2 led to the activation of apoptosis of the breast cancer cells. Inhibition of autophagy enhanced the cytotoxic effect of TBMS1 via promoting apoptosis. Our results demonstrate the role and mechanism of TBMS1 in activating autophagy, suggesting that inhibition of cytoprotective autophagy may act as a therapeutic strategy to reinforce the activity of TBMS1 against cancers.

Decreased expression of interleukin-37 in the ectopic and eutopic endometria of patients with adenomyosis.

Previous studies have shown that alterations of cytokines might play a role in the pathogenesis of adenomyosis. This study aims to investigate the expression of interleukin-37 (IL-37), an anti-inflammatory cytokine, in the eutopic and ectopic endometria of patients with adenomyosis. Endometrial specimens were collected from 30 women with adenomyosis and 20 without adenomyosis. The gene and protein expression of IL-37 was measured using a quantitative real-time polymerase chain reaction and immunohistochemistry, respectively. Compared with the control endometria, the protein expression level and gene level of IL-37 was significantly lower in both the ectopic and eutopic endometria of patients with adenomyosis. The gene and protein expressions of IL-37 in ectopic endometria were lower than those in eutopic endometria of patients with adenomyosis. Our results suggest that there was a low level of IL-37 in the eutopic and ectopic endometria of patients with adenomyosis, and an abnormal inflammatory response might occur in the endometria of patients with adenomyosis.

Suppression of eEF-2K-mediated autophagy enhances the cytotoxicity of raddeanin A against human breast cancer cells in vitro.

Recent evidence shows that raddeanin A (RA), an oleanane-type triterpenoid saponin extracted from Anemone raddeana Regel, exerts remarkable cytotoxicity against cancer cells in vitro and in vivo. In addition, RA has also been found to activate autophagy in human gastric cancer cells. In this study, we investigated the molecular mechanisms underlying RA-induced autophagy as well as the relationship between RA-induced autophagy and its cytotoxicity in human breast cancer cells in vitro. Treatment with RA (2-8 µmol/L) dose-dependently enhanced autophagy, as evidenced by increased LC3 levels in breast cancer cell lines T47D, MCF-7 and MDA-MB-231. Furthermore, the Akt-mTOR-eEF-2K signaling pathway was demonstrated to be involved in RA-induced activation of autophagy in the 3 breast cancer cell lines. Treatment with RA (2-10 µmol/L) dose-dependently induced apoptosis in the 3 breast cancer cell lines. Pretreatment with the autophagy inhibitor chloroquine (CQ, 20 µmol/L) significantly enhanced RA-caused cytotoxicity via promoting apoptosis. In conclusion, our results suggest that modulating autophagy can reinforce the cytotoxicity of RA against human breast cancer cells.

A Combination Therapy with Baicalein and Taxol Promotes Mitochondria-Mediated Cell Apoptosis: Involving in Akt/ß-Catenin Signaling Pathway.

Baicalein, a major flavonoid, possesses anticancer and anti-inflammatory activity. The aim of the study is to explore the efficiency of combination therapy with baicalein and taxol, as well as the molecular mechanism on antitumor activity. Human ovarian cancer cells were treated with different concentration of baicalein for 48 h, and cell viability was determined by MTT assay. Baicalein inhibited cell proliferation of ovarian cancer cells, and IC50 value of baicalein in A2780 cells, SKOV3 cells, and OVCAR cells was 46.23, 60.68, and 38.03 µM, respectively. The ovarian cancer cells were treated with 10 µM of baicalein combined with increasing concentration of taxol for 48 h, and the results demonstrated that combination therapy with baicalein and taxol had much higher antitumor effects compared with the monotherapy. The molecular mechanisms involving in combination therapy promoted the caspase-3 activity then leading to cleavage of poly-ADP-ribose polymerase, which increased the cell apoptosis of ovarian cancer cells. Moreover, Z-VAD-FMK treatment partially decreased the baicalein-induced proliferation inhibition in human ovarian cancer cells. Furthermore, baicalein induced apoptosis through activation of the activities of caspase-3,-9, and increased cytoplasmic cytochrome C release. Importantly, baicalein inhibited the growth of A2780 cells by inhibiting Akt/ß-catenin signaling pathway. In conclusion, our result revealed that baicalein combinated with taxol at low concentrations could exert synergistic antitumor effects in ovarian cancer cells through mitochondria-mediated cell apoptosis and Akt/ß-catenin signaling pathway. Baicalein has a promising potential to be developed as an antitumor compound, and combination therapy of baicalein and taxol exhibits an antitumor potential in clinical therapy for human ovarian cancers.

[Cisplatin inhibits proliferation of cervical carcinoma cell line by up-regulating Stat1 expression].

OBJECTIVE: To investigate the role of Stat1 gene in the proliferation and chemotherapeutic sensitivity of cervical cancer HeLa cells. METHODS: The protein expression of Stat1 in the Hela cells exposed to gradient concentrations of cisplatin (DDP) was detected by Western blotting with or without small interfering RNA (siRNA)-mediated Stat1 gene silencing. The effect of Sata1 silencing on the sensitivity to DDP and cell proliferation of the cells was tested using MTT assay and BrdU assay, and the expression of c-Myc was detected by Western blotting in the cells treated with siRNA and DDP. RESULTS: The expression of Stat1 in Hela cells exposed to DDP increased with the DDP concentrations, reaching 1.5 folds of the baseline at a DDP concentration of 5 mg/L and 2 folds at 10 mg/L. Stat1-siRNA effectively reduced Stat1 expression in Hela cells, promoted the cell proliferation, and enhanced the expression of c-Myc; DDP inhibited the cell growth and down-regulated c-Myc expression. Stat1-siRNA rescued DDP-induced inhibition of cell growth and c-Myc down-regulation. CONCLUSION: The expression of Stat1 is associated with DDP sensitivity in cervical cancer cells, and Stat1 silencing can increase the sensitivity to DDP and c-Myc expression of the cells.

Analysis of the efficacy of three treatment options for cesarean scar pregnancy management.

AIM: To assess three different methods in treating patients with cesarean scar pregnancy (CSP). METHODS: We evaluated pre-, intra- and postoperative conditions of 124 CSP patients in one of the three treatment groups, of which 37 patients underwent uterine curettage by hysteroscopy under ultrasound monitoring (group 1), 28 patients were treated with methotrexate followed by hysteroscopy (group 2) and 59 cases underwent uterine arterial embolization followed by hysteroscopy (group 3). The treatment options were determined based on the patients' conditions. RESULTS: Among all three groups, group 3 (uterine arterial embolization followed by hysteroscopy) had the least intraoperative blood loss and the highest success rate with curettage, but the highest hospitalization cost. Group 1 (only hysteroscopy) had the shortest length of hospitalization and the lowest cost, but the highest intraoperative blood loss and slowest recovery. Group 2 (methotrexate followed by hysteroscopy) had the longest period of hospitalization, and other indexes had fallen in between the other two groups. CONCLUSION: Among the three methods, uterine arterial embolization followed by hysteroscopy is the safest and most efficient method without considering the cost of hospitalization. Patients with a low level of ß-hCG may consider choosing hysteroscopy under ultrasound monitoring or methotrexate followed by hysteroscopy. The advantage is low cost of hospitalization; however, patients may be under relatively higher surgical risks and lower first time surgical success rate, especially for patients treated by hysteroscopy under ultrasound monitoring.

[Synchronous primary endometrial and fallopian tube cancers: one case report].

OBJECTIVE: A patient was admitted for menopause for 2 years and abnormal vaginal bleeding and abdominal pain for 2 months. Gynecological examination revealed uterine atrophy without abnormal findings in the bilateral adnexa. CA125 and CEA levels were normal. The patient underwent laparoscopically assisted vaginal hysterectomy with bilateral salpingo-oophorectomy. Pathological examination of the surgical specimens revealed synchronous primary cancers stage Ia in both the endometrium and the right fallopian tube. The patient then received 6 cycles of chemotherapy with oxaliplatin combined with docetaxel given intravenously and remained alive without evidence of recurrence. Synchronous primary endometrial and fallopian tube cancer is a rare clinical entity, and laparoscopic surgery with postoperative chemotherapy can be considered for stage I patients.

[Peritoneal fluid leptin concentration and endocrine hormone in patients with polycystic ovarian syndrome].

OBJECTIVE: To determine whether the infertile patients with polycystic ovarian syndrome (PCOS) is related to dysregulation of peritoneal fluid and serum leptin concentration, and to investigate the relationship between the leptin and some endocrine hormones in PCOS. METHODS: Twenty subjects with PCOS and 20 control women were included in the study. Peritoneal fluid and serum concentration of leptin, insulin, insulin-antibody, testosterone (T), estrogen (E(2)), and progestogen (P) were measured by radioimmunoassay (RIA). RESULTS: Peritoneal fluid concentrations of leptin, insulin, T and insulin-antibody in PCOS patients were significantly higher than those of the control group (P<0.05). There was no statistically significant difference in peritoneal fluid E(2) and P between PCOS and the control group (P>0.05). The serum concentrations of leptin and T in PCOS were significantly higher than those of the control group (P<0.05), but the levels of insulin, E(2), P and insulin-antibody were not significantly different between the 2 groups (P>0.05). With the BMI> or =23 kg/m(2) subgroup in PCOS patients, the peritoneal fluid and serum concentrations of leptin, insulin and T were significantly higher than those of BMI 23 kg/m(2) subgroup (P<0.01). There was no significant difference in E(2)and insulin-antibody between the 2 subgroups (P>0.05). Pearson correlation analysis indicated that peritoneal fluid and serum leptin levels were positively correlated with BMI, insulin, T and insulin-antibody, but negatively correlated with E(2), with no significant correlation with P. Multiple stepwise regression analysis indicated that the factors that influenced the peritoneal fluid and serum leptin levels were BMI, insulin, T and E(2) ordinally. CONCLUSION: Peritoneal fluid and serum leptin concentration and insulin,T, Ins-antibody level are abnormal in PCOS patients. Leptin may play an important role in the pathogenesis of PCOS. BMI is the main factor to correlate with leptin.