Involvement of autophagy in cervical, endometrial and ovarian cancer

Changes in cytokine and sequestosome-1 levels during twin pregnancy progression: Association with outcome

BACKGROUND

Twin pregnancies are associated with complications and adverse outcomes. The number of twin pregnancies has increased in the last decades, due to the use of assisted reproductive techniques and delayed childbearing. Analysis of changes that occur during twin pregnancy progression and their association with outcome will lead to improved clinical interventions.

OBJECTIVE

We evaluated if the plasma concentration of select cytokines and the level of sequestosome-1 (p62) in peripheral blood mononuclear cells (PBMCs) during each trimester of twin gestations was predictive of pregnancy outcome.

STUDY DESIGN

This prospective, observational study was conducted at Careggi University Hospital, Florence, Italy. Plasma from 82 women with twin pregnancies was collected in each trimester for measurement of interleukin (IL)-1β, IL-6, IL-10, IL-12 and tumor necrosis factor (TNF)-α. The intracellular PBMC concentration of p62, a protein involved in autophagy, kinase activity and cell differentiation, was also determined.

RESULTS

IL-1β (p < 0.001), IL-6 (p < 0.001), TNF-α (p < 0.001) and p62 (p < 0.05) increased from the 1st to the 2nd to the 3rd trimester. The TNF-α level was correlated with the IL-1β concentration in the 1st and 3rd trimesters p < 0.01) and with the IL-6 concentration in each of the three trimesters (p < 0.01). The intracellular p62 level in PBMCs was negatively correlated with the concentration of IL-1β in the 2nd trimester (p < 0.05) and negatively correlated with the IL-6 level in the 3rd trimester (p < 0.05). The TNF-α level was significantly higher in the 2nd (p < 0.05) and 3rd (p < 0.001) trimester in women with a spontaneous preterm delivery. The TNF-α concentrations in the 2nd (p < 0.05) and 3rd (p < 0.01) trimester, respectively, and 3rd trimester IL-6 (p < 0.01), were negatively associated with gestational age at delivery. The concentration of IL-6 was highest in the 2nd (p < 0.05) and 3rd (p < 0.05) trimesters in women who utilized assisted reproductive technologies. An elevated IL-1β level in the 3rd trimester was associated with gestational diabetes mellitus (p < 0.05).

CONCLUSION

Variations in cytokine levels between individual women during the three trimesters of twin gestations are predictive of spontaneous preterm delivery and the onset of gestational diabetes.

LncRNA STARD7-AS1 suppresses cervical cancer cell proliferation while promoting autophagy by regulating miR-31-5p/TXNIP axis to inactivate the mTOR signaling

OBJECTIVE

Cervical cancer (CC) is a serious gynecologic health issue for women worldwide. Long non-coding RNA (lncRNA) has been well-documented in controlling malignant behavior of various cancer cells. The role of lncRNA STARD7-AS1 in regulating CC cell proliferation and autophagy and its possible mechanism were investigated in this work.

METHODS

RNA expression and protein levels were quantified by reverse transcription quantitative polymerase chain reaction and western blotting. The location of STARD7-AS1 in CC cells was examined using subcellular fraction assays. Cell Counting Kit-8 assays and colony forming assays were performed to measure CC cell viability and proliferation. Autophagy in CC cells was evaluated using macrophage-derived chemokine (MDC) staining and transmission electron microscopy. The binding between microRNA (miR)-31-5p and STARD7-AS1 (or thioredoxin-interacting protein [TXNIP]) was determined by performing luciferase reporter, RNA pull-down or RNA immunoprecipitation assays.

RESULTS

STARD7-AS1 overexpression significantly suppressed CC cell viability and proliferation while notably inducing autophagy. STARD7-AS1 upregulated TXNIP expression via interaction with miR-31-5p. In addition, the effects of STARD7-AS1 on CC cell proliferation and autophagy were reversed by TXNIP silencing. The suppressive effect of STARD7-AS1 overexpression on phosphorylated levels of mTOR and S6K1 was countervailed by TXNIP deficiency.

CONCLUSION

In conclusion, lncRNA STARD7-AS1 inhibits CC cell proliferation and promotes cell autophagy by targeting the miR-31-5p/TXNIP axis to inactivate the mTOR signaling.

The sequestosome 1 protein: therapeutic vulnerabilities in ovarian cancer

Ovarian cancer (OC) is the most deadly tumor that may develop in a woman's reproductive system. It is also one of the most common causes of death among those who have been diagnosed with cancer in women. An adapter protein known as sequestosome 1(SQSTM1) or p62 is primarily responsible for the transportation, degradation, and destruction of a wide variety of proteins. This adapter protein works in conjunction with the autophagy process as well as the ubiquitin proteasome degradation pathway. In addition, the ability of SQSTM1 to interact with multiple binding partners link SQSTM1 to various pathways in the context of antioxidant defense system and inflammation. In this review, we outline the processes underlying the control that SQSTM1 has on these pathways and how their dysregulation contributes to the development of OC. At the final, the therapeutic approaches based on SQSTM1 targeting have been discussed.

FBXO5 acts as a novel prognostic biomarker for patients with cervical cancer

Background: Cervical cancer (CC) remains one of the most common and deadly malignancies in women worldwide. FBXO5, a protein-coding gene, is highly expressed in a variety of primary tumors and promotes tumor progression, however, its role and prognostic value in CC remain largely unknown. Methods: A key differential gene, FBXO5, was screened according to WGCNA based on immunohistochemical assays of clinical samples, multiple analyses of the Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases, including survival analysis, tumor mutational burden, GO, KEGG, tumor immune infiltration, and chemotherapeutic drug sensitivity, to explore the expression and prognostic value of FBXO5 in CC. The migration and invasiveness of cervical cancer cells following FBXO5 knockdown and overexpression were examined using wound healing and transwell assays, and the viability of cancer cells was assessed using CCK8 and EdU assays. Results: FBXO5 was discovered to be substantially expressed in CC tissues using data from our CC cohort and the TCGA database, and a survival analysis indicated FBXO5 as a predictive factor for poor overall survival in CC patients. In vitro, CC cells were more inclined to proliferate, migrate, and invade when FBXO5 was upregulated as opposed to when it was knocked down.

CCND1-Induced Autophagy Contributes to Lymph Node Metastasis in Endometrial Cancer

Endometrial cancer with lymph node metastasis shows poor prognosis, while the biomarker to predict the metastasis is lacking. The relative mRNA or protein expression of cyclin D1 (CCND1) and autophagy-related molecules were detected in real-time PCR and Western blot. Correlation analysis was applied to identify any significant patterns, and receiver operating characteristics (ROC) was performed to assess the prediction value. CCND1 vector was transfected in Ishikawa (ISK) cells, and the relative expression of autophagy-related molecules was detected with Western blot. CCND1 was overexpressed in endometrial cancer and correlated with lymph node metastasis. ROC analysis found that CCND1 had a predictive value to discriminate tumors from normal tissues (cut off=1.455; sensitivity, 71%; specificity, 84%; area under curve (AUC) 0.82; p<0.001) and had a predictive value to indicate metastasis (cut off=1.871; sensitivity, 54.17%; specificity, 75%; AUC 0.674; p=0.003). Increased BECLIN1 (r=0.39, p<0.001) and ATG5 (r=0.41, p<0.001) expression were positively correlated to CCND1. On the other hand, the relative protein expression of CCND1, BECLIN1, ATG5, ATG7, and LC3 I/II were also increased in tumor tissues. CCND1 overexpressed ISK cells showed upregulated BECLIN1, ATG5, ATG7, and LC3 I/II expression. CCND1 promoted autophagy may contribute to lymph node metastasis in endometrial cancer.

Autophagy: A challengeable paradox in cancer treatment

OBJECTIVE

Autophagy is an intracellular degradation pathway conserved in all eukaryotes from yeast to humans. This process plays a quality-control role by destroying harmful cellular components under normal conditions, maintaining cell survival, and establishing cellular adaptation under stressful conditions. Hence, there are various studies indicating dysfunctional autophagy as a factor involved in the development and progression of various human diseases, including cancer. In addition, the importance of autophagy in the development of cancer has been highlighted by paradoxical roles, as a cytoprotective and cytotoxic mechanism. Despite extensive research in the field of cancer, there are many questions and challenges about the roles and effects suggested for autophagy in cancer treatment. The aim of this study was to provide an overview of the paradoxical roles of autophagy in different tumors and related cancer treatment options.

METHODS

In this study, to find articles, a search was made in PubMed and Google scholar databases with the keywords Autophagy, Autophagy in Cancer Management, and Drug Design.

RESULTS

According to the investigation, some studies suggest that several advanced cancers are dependent on autophagy for cell survival, so when cancer cells are exposed to therapy, autophagy is induced and suppresses the anti-cancer effects of therapeutic agents and also results in cell resistance. However, enhanced autophagy from using anti-cancer drugs causes autophagy-mediated cell death in several cancers. Because autophagy also plays roles in both tumor suppression and promotion further research is needed to determine the precise mechanism of this process in cancer treatment.

CONCLUSION

We concluded in this article, autophagy manipulation may either promote or hinder the growth and development of cancer according to the origin of the cancer cells, the type of cancer, and the behavior of the cancer cells exposed to treatment. Thus, before starting treatment it is necessary to determine the basal levels of autophagy in various cancers.

HERPUD1 promotes ovarian cancer cell survival by sustaining autophagy and inhibit apoptosis via PI3K/AKT/mTOR and p38 MAPK signaling pathways

HERPUD1 is an important early marker of endoplasmic reticulum stress (ERS) and is involved in the ubiquitination and degradation of several unfolded proteins. However, its role in tumorigenesis is seldom studied, and its role in ovarian cancer is unclear. Lewis y antigen is a tumor-associated sugar antigen that acts as an 'antenna' on the cell surface to receive signals from both inside and outside the cell. We previously reported that Lewis y can promote ovarian cancer by promoting autophagy and inhibiting apoptosis. In this study, we detect the expression of HERPUD1 and Lewis y antigens in 119 different ovarian cancer tissues, determine their relationship with clinicopathological parameters, analyze the correlation between these two proteins, and explore the related cancer-promoting mechanisms through MTT, flow cytometry, western blotting, and bioinformatics. HERPUD1 is highly expressed in ovarian cancer, especially in the early stage, and the expression of HERPUD1 and Lewis y antigen was positively correlated. After overexpression of Lewis y antigen, the expression level of HERPUD1 increased. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathways (KEGG) analysis showed that HERPUD1 and its related genes are enriched in regulating immunity, endoplasmic reticulum stress, ubiquitin-dependent degradation, ERS-induced apoptosis, and other key signaling pathways. We also clarified the HERPUD1 network of kinases, microRNA and transcription factor targets, and the impact of HERPUD1 mutations on prognosis. In addition, HERPUD1 promotes the proliferation of ovarian cancer cells, inhibits apoptosis, affects the cell cycle, promotes the occurrence of autophagy, and inhibits EMT and PI3K/AKT/mTOR and p38MAPK pathways. Overall, HERPUD1, regulated by the expression of tumor-associated protein Lewis y, promotes cell survival in the early stages of tumors, suggesting that HERPUD1 may play an important role in the development of ovarian cancer.

CircRNF144B/miR-342-3p/FBXL11 axis reduced autophagy and promoted the progression of ovarian cancer by increasing the ubiquitination of Beclin-1

Circular RNAs (circRNAs) can regulate autophagy and ovarian cancer (OC) progression. However, autophagy-associated circRNAs involved in OC progression are largely unknown. Bioinformatics, RNA sequencing, and qRT-PCR were conducted to detect circRNF144B expression in OC as well as its relationship with patient prognosis. Functional experiments were used to determine the effects of circRNF144B on the proliferation, mobility and autophagy of OC. Double luciferase reporter assays, immunoprecipitation, and ubiquitination detection were performed to determine the molecular mechanisms of circRNF144B in autophagy and OC progression. CircRNF144B was elevated in OC tissues with low autophagy levels, and associated with poor prognosis. CircRNF144B promoted the malignant biological properties of OC cells, and inhibited the autophagy. Mechanistically, circRNF144B acts as a sponge for miR-342-3p and inhibits miR-342-3p-induced degradation of lysine demethylase 2 A (FBXL11) mRNA, leading to elevated FBXL11 protein levels. Elevated FBXL11 promoted the ubiquitination and degradation of Beclin-1, thus inhibiting autophagy. In conclusion, CircRNF144B increased FBXL11 level by sponging miR-342-3p, whereas elevated FBXL11 promoted the ubiquitination and protein degradation of Beclin-1, thus suppressing autophagy flux and promoting OC progression. Thus, circRNF144B may be an effective target for OC therapy.

Impact of Human Papillomavirus on Wnt/Beta-Catenin Signaling in Morphological Inconspicuous Cervicovaginal Cells

INTRODUCTION

The aim of this study was to identify early changes in the Wnt/beta-catenin signaling pathway in high-risk human papillomavirus (HPV) infected cervicovaginal cells and to correlate these changes with cell proliferation, apoptosis, and autophagic processes.

METHODS

We evaluated 91 cervicovaginal smears of women with (n = 41) and without (n = 50) HPV-DNA. Smears were stained against beta-catenin, c-myc, secreted frizzled-related protein 4 (sFRP4), cleaved caspase-3, and the autophagy markers Beclin-1 and light chain 3B. In addition, sFRP-1, -2, -3, -4, -5 mRNA levels were determined by quantitative reverse transcription-PCR in primary keratinocytes and FaDu cells expressing HPV16-E6, -E7, or -E6E7.

RESULTS

Our data indicated that the Wnt/beta-catenin signaling is activated in HPV (+) cervicovaginal cells that can already be detected in cells with no obvious changes in cellular morphology (HPV [+]/cyto [-]). These cells also had significantly higher sFRP4 levels when compared to HPV-negative samples. In primary keratinocytes, sFRP4 was found to be absent and sFRP1 and sFRP2 to be repressed in the presence of HPV16-E6 and E7. Interestingly, sFRP4 is expressed in FaDu cells and can be upregulated in the presence of E6E7. Curiously, SFRP4 expression correlated with an increase in the level of autophagic markers in HPV (+)/cyto (-) smears.

CONCLUSION

In conclusion, the activation of the Wnt/beta-catenin signaling pathway and upregulation of sFRP4, paralleled by an activation of the autophagic pathway may represent predisposing cellular factors early after HPV infection which need to be further determined in larger study.

Diane-35 and Metformin Induce Autophagy and Apoptosis in Polycystic Ovary Syndrome Women with Early-Stage Endometrial Carcinoma

Objective: Women with polycystic ovary syndrome (PCOS) are at increased risk ofendometrial carcinoma (EC). Previous studies indicated that the combined therapy of Diane-35 and metformin significantly suppresses disease progression in PCOS patients with early EC; however, the mechanisms remain unclear. Methods: An established murine model of PCOS with early EC, clinical specimens, and human EC cells was used in this study. The levels of protein and mRNA were measured with Western blotting and RT-PCR, respectively. Cell proliferation was determined with MTT, colony formation, and flow cytometry. Proteins were analyzed with immunofluorescence and immunohistochemistry. Results: Diane-35 and metformin significantly inhibited proliferative activity and promoted apoptosis in EC cells. Additionally, cell autophagy was induced by the combined therapy. Quantitive PCR revealed that Diane-35 and metformin decreased androgen receptor (AR) expression but elevated GLUT4 expression. AR was found to repress GLUT4 expression by binding to the promoter of GLUT4. Moreover, the combined treatment mediated the onset of cellular autophagy by regulating the mTORC pathway via the suppression of IGF-1 and inhibited the development of EC by the activation of the PI3K/mTORC pathway. Conclusion: The results and previous clinical evidence support the use of Diane-35 and metformin combination therapy for patients with PCOS and early EC.

Autophagy-related long non-coding RNA signature for potential prognostic biomarkers of patients with cervical cancer: a study based on public databases

Background

Metastasis and recurrence are the main causes of death from cervical cancer (CC), thus it is important to identify more effective biomarkers to improve its prognosis. The purpose of our research was to determine the potential role of autophagy-related long non-coding RNA (lncRNA) in CC and to construct an autophagy-related lncRNA signature for survival of CC.

Methods

The lncRNAs in CC were downloaded from The Cancer Genome Atlas (TCGA) database, and autophagy-related lncRNAs were identified through the co-expression of lncRNA genes and autophagy genes. Several autophagy-related lncRNAs with prognostic value (AC012306.2, AL109976.1, ATP2A1-AS1, ILF3-DT, Z83851.2, STARD7-AS1, AC099343.2, AC008771.1, DBH-AS1, and AC097468.3) were identified using univariate and multivariate Cox regression analyses and a prognostic signature was established. The signature effect was detected by univariate Cox regression analysis [hazard ratio (HR) =1.665; 95% confidence interval (CI): 1.331–2.082; P<0.001] and multivariate Cox regression analysis (HR =1.738; 95% CI: 1.359–2.223; P<0.001). A nomogram was drawn by risk score and clinical features.

Results

The prognostic signature could predict the survival of CC by survival-receiver operating characteristic (ROC) curve [area under the curve (AUC) =0.810]. A nomogram was drawn by risk score and clinical features, and its c-index and calibration curve demonstrated that the prognostic signature could independently predict the prognosis of CC (P<0.001). Gene set enrichment analysis (GSEA) confirmed that the genes were significantly enriched in cancer- and autophagy-related pathways (P<0.05).

Conclusions

This 10 autophagy-related lncRNA signature has prognostic potential for CC. More important roles in the CC biology of these lncRNAs may be identified with further study.

Alterations of the 70 kDa heat shock protein (HSP70) and sequestosome-1 (p62) in women with breast cancer

Peripheral blood mononuclear cells (PBMCs) respond to altered physiological conditions to alleviate the threat. Production of the 70 kDa heat shock protein (HSP70) is up-regulated to protect proteins from degradation. Sequestosome-1 (p62) binds to altered proteins and the p62-protein complex is degraded by autophagy. P62 is also a regulator of intracellular kinase activity and cell differentiation. We hypothesized that the PBMC response to a malignant breast mass involves elevated production of HSP70 and a decrease in intracellular p62. In this study 46 women had their breast mass excised. PBMCs were isolated and intracellular levels of HSP70 and p62 were quantitated by ELISA. Differences between women with a benign or malignant breast mass were determined. A breast malignancy was diagnosed in 38 women (82.6%) while 8 had a benign lesion. Mean intracellular HSP70 levels were 79.3 ng/ml in PBMCs from women with a malignant lesion as opposed to 44.2 ng/ml in controls (p = 0.04). The mean PBMC p62 level was 2.3 ng/ml in women with a benign breast lesion as opposed to 0.6 ng/ml in those with breast cancer (p < 0.001). Mean p62 levels were lowest in women with invasive carcinoma and a positive lymph node biopsy when compared to those with in-situ carcinoma or absence of lymphadenopathy, respectively. Intracellular HSP70 and p62 levels in PBMCs differ between women with a malignant or benign breast lesion. These measurements may be of value in the preoperative triage of women with a breast mass.

Functional profiles of Müllerian inhibiting substance/anti-Müllerian hormone (MIS/AMH) in primarily cultured endometrial cancer cells

Background: Müllerian inhibiting substance/anti-Müllerian hormone (MIS/AMH) inhibits proliferation of MIS/AMH receptor-expressing gynecologic tumors in vivo and in vitro, but the underlying mechanisms have not been fully defined. This study aimed to investigate the expression of MIS/AMH type II receptor (MIS/AMHRII) in endometrial cancer, to identify the mechanism of growth inhibition in MIS/AMH-treated endometrial cancer cells, and to evaluate the clinical significance of MIS/AMH as an effective targeted therapy for MIS/AMH receptor-expressing tumors.

Methods: We used tissue samples from 10 patients with total hysterectomy for endometrial cancer. To identify involved signaling pathways, we performed western blotting on apoptosis-, cell cycle-, Wnt signaling-, and autophagy-related proteins.

Results: MIS/AMHRII was highly expressed on the cell membrane of endometrial cancer tissues and primarily cultured endometrial cancer cells. We also found that MIS/AMH treatment reduced cell viability, induced cell cycle arrest, and increased apoptosis. MIS/AMH treatment induced upregulation of β-catenin-interacting protein (ICAT) and inhibition of the Dvl and Axin complex (IDAX) but downregulation of phospho-c-Jun in the Wnt signaling pathway.

Conclusions: MIS/AMH inhibits the growth of MIS/AMH receptor-expressing endometrial cancer cells through regulation of autophagy, apoptosis, and cell cycle pathways, as well as inhibition of Wnt signaling pathways. These data suggest that MIS/AMH functions as a tumor suppressor and may be an effective therapeutic agent in endometrial cancer.

Autophagy in the physiological endometrium and cancer

Autophagy is a highly conserved catabolic process and a major cellular pathway for the degradation of long-lived proteins and cytoplasmic organelles. An increasing body of evidence has unveiled autophagy as an indispensable biological function that helps to maintain normal tissue homeostasis and metabolic fitness that can also lead to severe consequences for the normal cellular functioning when altered. Recent accumulating data point to autophagy as a key player in a wide variety of physiological and pathophysiological conditions in the human endometrium, one of the most proficient self-regenerating tissues in the human body and an instrumental player in placental species reproductive function. The current review highlights the most recent findings regarding the process of autophagy in the normal and cancerous endometrial tissue. Current research efforts aiming to therapeutically exploit autophagy and the methodological approaches used are discussed.Abbreviations: 3-MA: 3-methyladenine; ACACA (acetyl-CoA carboxylase alpha); AICAR: 5-aminoimidazole-4-carboximide riboside; AKT: AKT serine/threonine kinase; AMPK: AMP-activated protein kinase; ATG: autophagy related; ATG12: autophagy related 12; ATG16L1: autophagy related 16 like 1; ATG3: autophagy related 3; ATG4C: autophagy related 4C cysteine peptidase; ATG5: autophagy related 5; ATG7: autophagy related 7; ATG9: autophagy related 9; Baf A1: bafilomycin A1; BAX: BCL2 associated X, apoptosis regulator; BCL2: BCL2 apoptosis regulator; BECN1: beclin 1; CACNA1D: calcium voltage-gated channel subunit alpha1 D; CASP3: caspase 3; CASP7: caspase 7; CASP8: caspase 8; CASP9: caspase 9; CD44: CD44 molecule (Indian blood group); CDH1: cadherin 1; CDKN1A: cyclin dependent kinase inhibitor 1A; CDKN2A: cyclin dependent kinase inhibitor 2A; CMA: chaperone-mediated autophagy; CQ: chloroquine; CTNNB1: catenin beta 1; DDIT3: DNA damage inducible transcript 3; EC: endometrial cancer; EGFR: epidermal growth factor receptor; EH: endometrial hyperplasia; EIF4E: eukaryotic translation initiation factor 4E; EPHB2/ERK: EPH receptor B2; ER: endoplasmic reticulum; ERBB2: er-b2 receptor tyrosine kinase 2; ERVW-1: endogenous retrovirus group W member 1, envelope; ESR1: estrogen receptor 1; FSH: follicle-stimulating hormone; GCG/GLP1: glucagon; GFP: green fluorescent protein; GIP: gastric inhibitory polypeptide; GLP1R: glucagon-like peptide-1 receptor; GLS: glutaminase; H2AX: H2A.X variant histone; HIF1A: hypoxia inducible factor 1 alpha; HMGB1: high mobility group box 1; HOTAIR: HOX transcript antisense RNA; HSPA5: heat shock protein family A (HSP70) member 5; HSPA8: heat shock protein family A (HSP70) member 8; IGF1: insulin like growth factor 1; IL27: interleukin 27; INS: insulin; ISL: isoliquiritigenin; KRAS: KRAS proto-oncogene, GTPase; LAMP2: lysosomal-associated membrane protein 2; lncRNA: long-non-coding RNA; MAP1LC3A/LC3A: microtubule associated protein 1 light chain 3 alpha; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MAPK8: mitogen-activated protein kinase 8; MAPK9: mitogen-activated protein kinase 9; MPA: medroxyprogesterone acetate; MTOR: mechanistic target of rapamycin kinase; MTORC1: mechanistic target of rapamycin kinase complex 1; MTORC2: mechanistic target of rapamycin kinase complex 2; MYCBP: MYC-binding protein; NFE2L2: nuclear factor, erythroid 2 like 2; NFKB: nuclear factor kappa B; NFKBIA: NFKB inhibitor alpha; NK: natural killer; NR5A1: nuclear receptor subfamily 5 group A member 1; PARP1: poly(ADP-ribose) polymerase 1; PAX2: paired box 2; PDK1: pyruvate dehydrogenase kinase 1; PDX: patient-derived xenograft; PIK3C3/Vps34: phosphatidylinositol 3-kinase catalytic subunit type 3; PIK3CA: phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha; PIK3R1: phosphoinositide-3-kinase regulatory subunit 1; PIKFYVE: phosphoinositide kinase, FYVE-type zinc finger containing; PPD: protopanaxadiol; PRKCD: protein kinase C delta; PROM1/CD133: prominin 1; PtdIns3K: class III phosphatidylinositol 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate; PTEN: phosphatase and tensin homolog; RB1CC1/FIP200: RB1 inducible coiled-coil 1; RFP: red fluorescent protein; RPS6KB1/S6K1: ribosomal protein S6 kinase B1; RSV: resveratrol; SGK1: serum/glucocorticoid regulated kinase 1; SGK3: serum/glucocorticoid regulated kinase family member 3; SIRT: sirtuin; SLS: stone-like structures; SMAD2: SMAD family member 2; SMAD3: SMAD family member 3; SQSTM1: sequestosome 1; TALEN: transcription activator-like effector nuclease; TGFBR2: transforming growth factor beta receptor 2; TP53: tumor protein p53; TRIB3: tribbles pseudokinase 3; ULK1: unc-51 like autophagy activating kinase 1; ULK4: unc-51 like kinase 4; VEGFA: vascular endothelial growth factor A; WIPI2: WD repeat domain, phosphoinositide interacting 2; XBP1: X-box binding protein 1; ZFYVE1: zinc finger FYVE domain containing 1.

α-Tomatine, a novel early-stage autophagy inhibitor, inhibits autophagy to enhance apoptosis via Beclin-1 in Skov3 cells

Targeting the autophagy process is considered to be a promising new strategy for drug treatment of ovarian cancer. α-Tomatine, a steroidal alkaloid extracted, is mainly isolated from leaves, roots and immature green tomatoes. α-Tomatine has biological activities such as anticancer, antioxidative and anti-inflammatory. The study aimed to explore the effects of α-tomatine on proliferation, apoptosis and autophagy and the underlying mechanisms in ovarian cancer Skov3 cells. After treatment with different concentrations of α-tomatine (0, 0.75, 1 and 1.5 μM) in Skov3 cells for 24 h, proliferation was determined by the CCK-8 assay, and apoptosis was detected by flow cytometric analysis. Autophagy in cells was determined by the number of fluorescent spots using confocal fluorescence microscopy after mRFP-GFP-LC3 transfection. The relationship between autophagy and apoptosis was proved by Beclin-1 overexpression. The protein expression levels were tested by western blotting. The results demonstrated that α-tomatine effectively repressed proliferation, exerted a proapoptotic effect and inhibited early-stage autophagy in Skov3 cells in a dose- and time-dependent manner. Additionally, Beclin-1 overexpression significantly suppressed α-tomatine-treated apoptosis in Skov3 cells, indicating that α-tomatine inhibits autophagy to induce apoptosis. We also found α-tomatine inhibited the protein expression levels of PI3K/Akt/mTOR signaling pathway. However, the autophagy inhibition of α-tomatine could be reversed obviously by Beclin-1 overexpression. Taken together, α-tomatine inhibited autophagy through Beclin-1. Our study suggests that α-tomatine, as a novel early-stage autophagy inhibitor, might be a potential drug for further treatment of ovarian cancer by inhibiting proliferation and promoting apoptosis.

Construction autophagy-related prognostic risk signature to facilitate survival prediction, individual treatment and biomarker excavation of epithelial ovarian cancer patients

Background

Existing clinical methods for prognosis evaluating for Epithelial Ovarian Cancer (EOC) patients had defects of invasive, unsystematic and subjective and little data are available for individualizing treatment, therefore, to identify potential prognostic markers and new therapeutic targets for EOC is urgently required.

Results

Expression of 232 autophagy-related genes (ARGs) in 354 EOC and 56 human ovarian surface epithelial specimens from 7 independent laboratories were analyzed, 31 mRNAs were identified as DEARGs. We did functional and pathway enrichment analysis and constructed protein–protein interaction network for all DEARGs. To screen out candidate DEARGs related to EOC patients’ survival and construct an autophagy-related prognostic risk signature, univariate and multivariate Cox proportional hazards models were established separately. Finally, 5 optimal independent prognostic DEARGs (PEX3, DNAJB9, RB1, HSP90AB1 and CXCR4) were confirmed and the autophagy-related risk model was established by the 5 prognostic DEARGs. The accuracy and robustness of the prognostic risk model for survival prediction were evaluated and verified by analyzing the correlation between EOC patients’ survival status, clinicopathological features and risk scores.

Conclusions

The autophagy-related prognostic risk model can be independently used to predict overall survival in EOC patients, it can also potentially assist in individualizing treatment and biomarker development.

Autophagy signals orchestrate chemoresistance of gynecological cancers

Gynecological cancers are characterized by a high mortality rate when chemoresistance develops. Autophagy collaborates with apoptosis and participates in homeostasis of chemoresistance. Recent findings supported that crosstalk of necrotic, apoptotic and autophagic factors, and chemotherapy-driven hypoxia, oxidative stress and ER stress play critical roles in chemoresistance in gynecological cancers. Meanwhile, current studies have shown that autophagy could be regulated by and cooperate with metabolic regulator, survival factors, stemness factors and specific post-translation modification in chemoresistant tumor cells. Meanwhile, non-coding RNA and autophagy crosstalk also contribute to the chemoresistance. Until now, analysis of individual autophagy factors towards the clinical significance and chemoresistance in gynecological cancer is still lacking. We suggest comprehensive integrated analysis of cellular homeostasis and tumor microenvironment to clarify the role of autophagy and the associated factors in cancer progression and chemoresistance. Panel screening of pan-autophagic factors will pioneer the development of risk models for predicting efficacy of chemotherapy and guidelines for systematic treatment and precision medicine.

Prognostic value of an autophagy-related long-noncoding-RNA signature for endometrial cancer

This study retrieved the transcriptome profiling data of 552 endometrial cancer (EC) patients from the TCGA (The Cancer Genome Atlas) database, and identified 1297 lncRNAs (long noncoding RNAs) related to autophagy genes using Pearson correlation analysis. Univariate Cox regression analysis of the training data set revealed that 14 autophagy-related lncRNAs had significantly prognostic value for endometrial cancer (P < 0.01). Multivariate Cox regression analysis of these autophagy-related lncRNAs established the following autophagy-related lncRNA prognosis signature for endometrial cancer: PI = (0.255 × AC005229.4 expression) + (0.405 × BX322234.1 expression) + (0.169 × FIRRE expression value) + (-0.122 × RAB11B-AS1 expression) + (-0.338 × AC003102.1 expression). This signature was validated in both the testing data set and the entire data set. The areas under the receiver operating characteristics curves for the 1-, 3-, and 5-year overall survival rates in the entire data set were 0.772, 0.733, and 0.714, respectively. In addition, a gene set enrichment analysis confirmed that cancer-related and autophagy-related pathways were significantly up-regulated in the high-risk group. In summary, this study has demonstrated that a signature comprising five autophagy-related lncRNAs has potential as an independent prognostic indicator of endometrial cancer, and also that these lncRNAs may play a key role in the development of endometrial cancer.

FTO accelerates ovarian cancer cell growth by promoting proliferation, inhibiting apoptosis, and activating autophagy

OBJECTIVE

Fat mass and obesity-associated protein (FTO) is identified as a critical demethylase involved in various physiological processes. Despite efforts have been made to study the biological functions of FTO in certain cancers, the role of FTO in ovarian cancer is largely unknown. In this study, we sought to investigate the function of FTO on proliferation, apoptosis and autophagy of ovarian cancer cells.

METHODS

Quantitative real-time PCR was performed to detect FTO expression in ovarian tumor tissues and ovarian cancer cell lines OVCAR-3, SKOV-3, COC1, HO-8910 and A2780. SKOV-3 cells were constructed with FTO overexpression and A2780 cells were constructed with FTO knockdown. CCK-8 assay was used to examine cell viability and flow cytometry was used to detect cell apoptosis. Activity assay kits were applied to detect caspase-3 and caspase-9 levels. Western blot was performed to measure the expressions of FTO, PCNA, Bax, Bcl-2, LC3, ATG5, P62, p-AKT and AKT. Stable FTO-overexpression SKOV-3 cells or FTO-depletion A2780 cells were injected subcutaneously into male Balb/c-nu mice. Xenografted tumors were assayed by H&E staining. Immunohistochemistry was subjected to measure FTO and Ki67 expressions.

RESULTS

FTO was up-regulated in ovarian tumor tissues compared with non-cancerous ovarian tissues. FTO overexpression markedly increased viability and autophagy function, but decreased apoptosis of ovarian cancer cells. In addition, FTO overexpression promoted AKT phosphorylation. In contrast, FTO silence showed the opposite effect.

CONCLUSION

FTO accelerated ovarian cancer cell growth by promoting proliferation, inhibiting apoptosis, and activating autophagy.

miR-106a Regulates Cell Proliferation and Autophagy by Targeting LKB1 in HPV-16-Associated Cervical Cancer

miR-106a is aberrantly regulated in various tumors and plays an important role in carcinogenesis. However, the biological role and molecular mechanism by which miR-106a contributes to cervical squamous cell carcinoma (CSCC) remains elusive. In this study, we verified that miR-106a was elevated in both human papilloma virus (HPV) 16-positive CSCC tissues and cell lines. ROC curve analysis showed that miR-106a could well distinguish HPV-16-positive CSCC tissues from normal cervical squamous epithelium tissues. High expression of miR-106a was associated with malignant clinicopathologic parameters in CSCC tissues. Exogenous expression of miR-106a greatly promoted cervical cancer cell proliferation while attenuated autophagy. Furthermore, a novel target of miR-106a, liver kinase B1 (LKB1), a proven tumor suppressor in cervical cancer was verified. Here we confirmed LKB1 was negatively correlated with malignant clinicopathologic parameters in CSCC tissues. Overexpression of LKB1 neutralized the effect of miR-106a on proliferation and autophagy in cervical cancer cell lines. In addition, the role of miR-106a in cell proliferation and autophagy was via LKB1 and its downstream pathway AMP-activated protein kinase-mammalian target of rapamycin. Of note, miR-106a was upregulated by HPV-16 E7 protein. The function of HPV-16 E7 to cell proliferation was suppressed when knockdown miR-106a in HPV-16 E7-expressing cells. IMPLICATIONS: Our study highlights the tumorigenic role and regulatory mechanism of miR-106a in CSCC. miR-106a may be a potential therapeutic target in HPV-associated cervical cancer.

Annona coriacea Mart. Fractions Promote Cell Cycle Arrest and Inhibit Autophagic Flux in Human Cervical Cancer Cell Lines

Plant-based compounds are an option to explore and perhaps overcome the limitations of current antitumor treatments. Annona coriacea Mart. is a plant with a broad spectrum of biological activities, but its antitumor activity is still unclear. The purpose of our study was to determine the effects of A. coriacea fractions on a panel of cervical cancer cell lines and a normal keratinocyte cell line. The antitumor effect was investigated in vitro by viability assays, cell cycle, apoptosis, migration, and invasion assays. Intracellular signaling was assessed by Western blot, and major compounds were identified by mass spectrometry. All fractions exhibited a cytotoxic effect on cisplatin-resistant cell lines, SiHa and HeLa. C3 and C5 were significantly more cytotoxic and selective than cisplatin in SiHa and Hela cells. However, in CaSki, a cisplatin-sensitive cell line, the compounds did not demonstrate higher cytotoxicity when compared with cisplatin. Alkaloids and acetogenins were the main compounds identified in the fractions. These fractions also markedly decreased cell proliferation with p21 increase and cell cycle arrest in G2/M. These effects were accompanied by an increase of H2AX phosphorylation levels and DNA damage index. In addition, fractions C3 and C5 promoted p62 accumulation and decrease of LC3II, as well as acid vesicle levels, indicating the inhibition of autophagic flow. These findings suggest that A. coriacea fractions may become effective antineoplastic drugs and highlight the autophagy inhibition properties of these fractions in sensitizing cervical cancer cells to treatment.

Role of Endometrial Autophagy in Physiological and Pathophysiological Processes

Endometrium is the mucosal lining of the uterus which expressed a cyclic process of proliferation, secretion and scaling under the control of hormones secreted by the ovary, and it also plays an indispensable role in the embryo implantation, the constitution of fetal-maternal interface, and the maintaining of pregnancy. In pathophysiological conditions, the abnormality or disorder of endometrium may lead to endometrium-related diseases, such as endometriosis, endometrium hyperplasia and even endometrial carcinoma. In recent years, more and more evidence revealed that autophagy exists in both the endometrium stroma cells and epithelial cells, and the activity of autophagy is changed in the different phases of menstruation, as well as in the endometrium-related diseases. Here, we aim to review the activity level, the regulatory factors and the function of autophagy in physiological and pathophysiological endometria, and to discuss the potential value of autophagy as a target for therapies of endometrium-related diseases.

Metformin combined with nelfinavir induces SIRT3/mROS-dependent autophagy in human cervical cancer cells and xenograft in nude mice

The molecular mechanisms underlying the antineoplastic properties of metformin combined with nelfinavir remain elusive. To explore this question, transmission electron microscopy (TEM) was used to observe the combinatorial effect of inducing autophagosome formation in human cervical cancer cells. Western blotting respectively assayed protein expression of LC3I, LC3II, Beclin-1, Autophagy-related protein 7 (Atg7), Autophagy-related protein 3 (Atg3), NAD-dependent deacetylase sirtuin-3 (SIRT3) and major histocompatibility complex class I chain-related gene A (MICA). Lactate dehydrogenase (LDH) cytotoxicity assay evaluated natural killer (NK) cell cytotoxicity in the presence of metformin and nelfinavir in combination or each drug alone. Using tumor xenografts in a nude mouse model, antitumor efficacy of the drug combination was assessed. We found that the drug combination could induce autophagosome formation in human cervical cancer cells. The biomarker proteins of autophagy, including Beclin-1, Atg7 and Atg3, decreased, but the ratios of LC3I/II increased. We also found that this drug combination sensitizes human cervical cancer cells to NK cell-mediated lysis by increasing the protein of SIRT3 and MICA. Moreover, this drug combination markedly induced autophagy of SiHa xenografts in nude mice. Therefore, it can be concluded that metformin, in combination with nelfinavir, can induce SIRT3/mROS-dependent autophagy and sensitize NK cell-mediated lysis in human cervical cancer cells and cervical cancer cell xenografts in nude mice. Thus, our findings have revealed the detailed molecular mechanisms underlying the antitumor effects of metformin in combination with nelfinavir in cervical cancer.

Lactic acid alleviates stress: good for female genital tract homeostasis, bad for protection against malignancy

Women are unique from all other mammals in that lactic acid is present at high levels in the vagina during their reproductive years. This dominance may have evolved in response to the unique human lifestyle and a need to optimally protect pregnant women and their fetuses from endogenous and exogenous insults. Lactic acid in the female genital tract inactivates potentially pathogenic bacteria and viruses, maximizes survival of vaginal epithelial cells, and inhibits inflammation that may be damaging to the developing fetus and maintenance of the pregnancy. In an analogous manner, lactic acid production facilitates survival of malignantly transformed cells, inhibits activation of immune cells, and prevents the release of pro-inflammatory mediators in response to tumor-specific antigens. Thus, the same stress-reducing properties of lactic acid that promote lower genital tract health facilitate malignant transformation and progression.

Autophagy as an emerging therapy target for ovarian carcinoma

Autophagy is a conserved cellular self-digestion pathway for maintenance of homeostasis under basal and stressed conditions. Autophagy plays pivotal roles in the pathogenesis of many diseases, such as aging-related diseases, autoimmune diseases, cardiovascular diseases, and cancers. Of special note is that accumulating data suggest an intimate relationship between autophagy and ovarian carcinoma. Autophagy is well identified to act as either as a tumor-suppressor or as a tumor-promoter in ovarian carcinoma. The exact function of autophagy in ovarian carcinoma is highly dependent on the circumstances of cancer including hypoxic, nutrient-deficient, chemotherapy and so on. However, the mechanism underlying autophagy associated with ovarian carcinoma remains elusive, the precise role of autophagy in ovarian carcinoma also remains undetermined. In this review, we tried to sum up and discuss recent research achievements of autophagy in ovarian cancer. Moreover, waves of novel therapies ways for ovarian carcinoma based on the functions of autophagy were collected.

The metabolic cross-talk between epithelial cancer cells and stromal fibroblasts in ovarian cancer progression: Autophagy plays a role

Cancer and stromal cells, which include (cancer‐associated) fibroblasts, adipocytes, and immune cells, constitute a mixed cellular ecosystem that dynamically influences the behavior of each component, creating conditions that ultimately favor the emergence of malignant clones. Ovarian cancer cells release cytokines that recruit and activate stromal fibroblasts and immune cells, so perpetuating a state of inflammation in the stroma that hampers the immune response and facilitates cancer survival and propagation. Further, the stroma vasculature impacts the metabolism of the cells by providing or limiting the availability of oxygen and nutrients. Autophagy, a lysosomal catabolic process with homeostatic and prosurvival functions, influences the behavior of cancer cells, affecting a variety of processes such as the survival in metabolic harsh conditions, the invasive growth, the development of immune and chemo resistance, the maintenance of stem‐like properties, and dormancy. Further, autophagy is involved in the secretion and the signaling of promigratory cytokines. Cancer‐associated fibroblasts can influence the actual level of autophagy in ovarian cancer cells through the secretion of pro‐inflammatory cytokines and the release of autophagy‐derived metabolites and substrates. Interrupting the metabolic cross‐talk between cancer cells and cancer‐associated fibroblasts could be an effective therapeutic strategy to arrest the progression and prevent the relapse of ovarian cancer.

Inhibition of autophagy protein LC3A as a therapeutic target in ovarian clear cell carcinomas

Objective

Ovarian clear cell carcinoma (CCC) is one of histological subtypes showing poor prognosis due to chemoresistance. The association of autophagy-related proteins and clinical implementation in CCC has not been determined.

Methods

The present study investigated whether expression of autophagy-related protein, light chain 3A (LC3A), was related with prognoses in the patients with CCC using immuno-histochemical stainings, and whether inhibition of autophagy modified the sensitivity to cisplatin in CCC cells in vitro.

Results

High expression of autophagy-related protein, LC3A, was detected in 78 cases (78%) in all CCC cases. The patients with high LC3A expression showed significantly lower response rate to primary chemotherapy (17% vs. 100%, p<0.010), and had worse progression-free survival (PFS) and overall survival (OS) compared with those with LC3A low expression. Furthermore, multivariate analyses revealed that high expression of LC3A was identified as independent worse prognostic factors for PFS and OS. Inhibition of autophagy protein LC3A using hydroxychloroquine (HCQ) increased sensitivity to cisplatin in CCC cells in vitro.

Conclusion

High expression of LC3A proteins was associated with lower response to platinum therapy, leading to worse prognoses in CCC. Although further studies are needed to confirm the results, inhibition of autophagy by HCQ was associated with platinum sensitivity. Autophagy protein LC3A could be a promising target for treatment for CCC.

Autophagy orchestrates adaptive responses to targeted therapy in endometrial cancer

Targeted therapies in endometrial cancer (EC) using kinase inhibitors rarely result in complete tumor remission and are frequently challenged by the appearance of refractory cell clones, eventually resulting in disease relapse. Dissecting adaptive mechanisms is of vital importance to circumvent clinical drug resistance and improve the efficacy of targeted agents in EC. Sorafenib is an FDA-approved multitarget tyrosine and serine/threonine kinase inhibitor currently used to treat hepatocellular carcinoma, advanced renal carcinoma and radioactive iodine-resistant thyroid carcinoma. Unfortunately, sorafenib showed very modest effects in a multi-institutional phase II trial in advanced uterine carcinoma patients. Here, by leveraging RNA-sequencing data from the Cancer Cell Line Encyclopedia and cell survival studies from compound-based high-throughput screenings we have identified the lysosomal pathway as a potential compartment involved in the resistance to sorafenib. By performing additional functional biology studies we have demonstrated that this resistance could be related to macroautophagy/autophagy. Specifically, our results indicate that sorafenib triggers a mechanistic MAPK/JNK-dependent early protective autophagic response in EC cells, providing an adaptive response to therapeutic stress. By generating in vivo subcutaneous EC cell line tumors, lung metastatic assays and primary EC orthoxenografts experiments, we demonstrate that targeting autophagy enhances sorafenib cytotoxicity and suppresses tumor growth and pulmonary metastasis progression. In conclusion, sorafenib induces the activation of a protective autophagic response in EC cells. These results provide insights into the unopposed resistance of advanced EC to sorafenib and highlight a new strategy for therapeutic intervention in recurrent EC.

Elaiophylin, a novel autophagy inhibitor, exerts antitumor activity as a single agent in ovarian cancer cells

Currently, targeting the autophagic pathway is regarded as a promising new strategy for cancer drug discovery. Here, we screened the North China Pharmaceutical Group Corporation's pure compound library of microbial origin using GFP-LC3B-SKOV3 cells and identified elaiophylin as a novel autophagy inhibitor. Elaiophylin promotes autophagosome accumulation but blocks autophagic flux by attenuating lysosomal cathepsin activity, resulting in the accumulation of SQSTM1/p62 in various cell lines. Moreover, elaiophylin destabilizes lysosomes as indicated by LysoTracker Red staining and CTSB/cathepsin B and CTSD/ cathepsin D release from lysosomes into the cytoplasm. Elaiophylin eventually decreases cell viability, especially in combination with cisplatin or under hypoxic conditions. Furthermore, administration of a lower dose (2 mg/kg) of elaiophylin as a single agent achieves a significant antitumor effect without toxicity in an orthotopic ovarian cancer model with metastasis; however, high doses (8 mg/kg) of elaiophylin lead to dysfunction of Paneth cells, which resembles the intestinal phenotype of ATG16L1-deficient mice. Together, these results provide a safe therapeutic window for potential clinical applications of this compound. Our results demonstrate, for the first time, that elaiophylin is a novel autophagy inhibitor, with significant antitumor efficacy as a single agent or in combination in human ovarian cancer cells, establishing the potential treatment of ovarian cancer by this compound.

Inhibition of autophagy in peripheral blood mononuclear cells by vaginal fluid from women with a malignant adnexal mass

Inhibition of autophagy is a characteristic of ovarian cancer. We determined whether inhibition of autophagy by vaginal fluid could provide a non-invasive test for cancer risk stratification in women presenting with an adnexal mass. Vaginal fluid supernatants from 90 women undergoing evaluation for a suspicious adnexal mass were incubated with peripheral blood mononuclear cells (PBMCs) obtained from healthy women under conditions that induce autophagy. Rapamycin, an autophagy inducer, was added to some cultures. After 48 hr the cells were collected, lysed and assayed by ELISA for intracellular p62 concentration. p62 is a cytoplasmic protein that is consumed during autophagy induction. Its concentration is inversely proportional to the extent of autophagy induction. Clinical information including pathological diagnoses was obtained after completion of laboratory studies. Mean p62 levels were 9.4 ng/ml in the 21 women with a subsequent malignant diagnosis, 4.5 ng/ml in the eight women with a borderline tumor diagnosis and 3.6 ng/ml in the 61 women with benign disease (p < 0.0001, malignant vs. others). When rapamycin was added to the vaginal fluid-PBMC co-incubation, p62 levels in samples from women with a malignant diagnosis decreased to 3.3 ng/ml, a level comparable to what was observed with the nonmalignant samples. Vaginal fluid inhibition of autophagy can differentiate between women with malignant and benign adnexal masses.