Effects of Kras activation and Pten deletion alone or in combination on MUC1 biology and epithelial-to-mesenchymal transition in ovarian cancer

Extracellular vesicle-encapsulated microRNA-296-3p from cancer-associated fibroblasts promotes ovarian cancer development through regulation of the PTEN/AKT and SOCS6/STAT3 pathways

Cancer-associated fibroblasts (CAFs), as important components of the tumor microenvironment, can regulate intercellular communication and tumor development by secreting extracellular vesicles (EVs). However, the role of CAF-derived EVs in ovarian cancer has not been fully elucidated. Here, using an EV-microRNA sequencing analysis, we reveal specific overexpression of microRNA (miR)-296-3p in activated CAF-derived EVs, which can be transferred to tumor cells to regulate the malignant phenotypes of ovarian cancer cells. Moreover, overexpression of miR-296-3p significantly promotes the proliferation, migration, invasion, and drug resistance of ovarian cancer cells in vitro, as well as tumor growth in vivo, while its inhibition has the opposite effects. Further mechanistic studies reveal that miR-296-3p promotes ovarian cancer progression by directly targeting PTEN and SOCS6 and activating AKT and STAT3 signaling pathways. Importantly, increased expression of miR-296-3p encapsulated in plasma EVs is closely correlated with tumorigenesis and chemoresistance in patients with ovarian cancer. Our results highlight the cancer-promoting role of CAF-derived EVs carrying miR-296-3p in ovarian cancer progression for the first time, and suggest that miR-296-3p encapsulated in CAF-derived EVs could be a diagnostic biomarker and therapeutic target for ovarian cancer.

An integrated analysis of dysregulated SCD1 in human cancers and functional verification of miR-181a-5p/SCD1 axis in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC), one of the most lethal cancers, has become a global health issue. Stearoyl-coA desaturase 1 (SCD1) has been demonstrated to play a crucial role in human cancers. However, pan-cancer analysis has revealed little evidence to date. In the current study, we systematically inspected the expression patterns and potential clinical outcomes of SCD1 in multiple human cancers. SCD1 was dysregulated in several types of cancers, and its aberrant expression acted as a diagnostic biomarker, indicating that SCD1 may play a role in tumorigenesis. We used ESCC as an example to demonstrate that SCD1 was dramatically upregulated in tumor tissues of ESCC and was associated with clinicopathological characteristics in ESCC patients. Furthermore, Kaplan-Meier analysis showed that high SCD1 expression was correlated with poor progression-free survival (PFS) and disease-free survival (DFS) in ESCC patients. The protein-protein interaction (PPI) network and module analysis by PINA database and Gephi were performed to identify the hub targets. Meanwhile, the functional annotation analysis of these hubs was constructed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Functionally, the gain-of-function of SCD1 in ESCC cells promoted cell proliferation, migration, and invasion; in contrast, loss-of-function of SCD1 in ESCC cells had opposite effects. Bioinformatic, QPCR, Western blotting and luciferase assays indicated that SCD1 was a direct target of miR-181a-5p in ESCC cells. In addition, gain-of-function of miR-181a-5p in ESCC cells reduced the cell growth, migratory, and invasive abilities. Conversely, inhibition of miR-181a-5p expression by its inhibitor in ESCC cells had opposite biological effects. Importantly, reinforced SCD1 in miR-181a-5p mimic ESCC transfectants reversed miR-181a-5p mimic-prevented malignant phenotypes of ESCC cells. Taken together, these results indicate that SCD1 expression influences tumor progression in a variety of cancers, and the miR-181a-5p/SCD1 axis may be a potential therapeutic target for ESCC treatment.

Eliciting effective tumor immunity against ovarian cancer by cancer stem cell vaccination

Advanced ovarian cancer (OC) patients have limited benefit from current relevant cytotoxic and targeted therapies following debulking surgery. Therefore, new therapeutic strategies are in urgent need. Immunotherapy has shown great potential in tumor treatment, especially in tumor vaccine development. The study objective was to evaluate the immune effects of cancer stem cells (CSCs) vaccines on OC. The CD44⁺CD117⁺CSCs were isolated from human OC HO8910 and SKOV3 cells using the magnetic cell sorting system; the cancer stem-like cells were selected from murine OC ID8 cell by no-serum formed sphere culture. The CSC vaccines were prepared by freezing and thawing these CSCs, which were then injected into mice followed by challenging the different OC cells. The in vivo antitumor efficacy of CSC immunization revealed the vaccines were capable of significantly provoking immune responses to autologous tumor antigens in vaccinated mice as the mice were found to have markedly inhibited tumor growth, prolonged survival, and decreased CSC counts in OC tissues when compared to mice without the CSC vaccination. The in vitro cytotoxicities of immunocytes toward SKOV3, HO8910 and ID8 cells indicated a significant killing efficacy compared with the controls. However, the antitumor efficacy was remarkably reduced whilst the mucin-1 expression in CSC vaccines was down-regulated by small interfering RNA. Overall, findings from this study provided the evidence that has deepened our understanding of CSC vaccine immunogenicity and anti-OC efficacy, particularly for the role of dominant antigen mucin-1. It is possible to turn the CSC vaccine into an immunotherapeutic approach against ovarian cancer.

The multifaced role and therapeutic regulation of autophagy in ovarian cancer

Ovarian cancer (OC) is one of the tumors that occurs most frequently in women. Autophagy is involved in cell homeostasis, biomolecule recycling, and survival, making it a potential target for anti-tumor drugs. It is worth noting that growing evidence reveals a close link between autophagy and OC. In the context of OC, autophagy demonstrates activity as both a tumor suppressor and a tumor promoter, depending on the context. Autophagy's exact function in OC is greatly reliant on the tumor microenvironment (TME) and other conditions, such as hypoxia, nutritional deficiency, chemotherapy, and so on. However, what can be concluded from different studies is that autophagy-related signaling pathways, especially PI3K/AKT/mTOR axis, increase in advanced stages and malignant phenotype of the disease reduces autophagy and ultimately leads to tumor progression. This study sought to present a thorough understanding of the role of autophagy-related signaling pathways in OC and existing therapies targeting these signaling pathways.

Metabolomic Pathway Activity with Genomic Single-Nucleotide Polymorphisms Associated with Colorectal Cancer Recurrence and 5-Year Overall Survival

PURPOSE

Metabolomic analysis in colorectal cancer (CRC) is an emerging research area with both prognostic and therapeutic targeting potential. We aimed to identify metabolomic pathway activity prognostic for CRC recurrence and overall survival and cross-reference such metabolomic data with prognostic genomic single-nucleotide polymorphisms (SNPs).

METHODS

A systematic search of PubMed, Embase and Cochrane Library was performed for studies reporting prognostic metabolomic pathway activity in CRC in keeping with PRISMA guidelines. The QUADOMICS tool was used to assess study quality. MetaboAnalyst software (version4.0) was used to map metabolites that were associated with recurrence and survival in CRC to recognise metabolic pathways and identify genomic SNPs associated with CRC prognosis, referencing the following databases: Human Metabolome Database (HMDB), the Small Molecule Pathway Database (SMPDB), PubChem and Kyoto Encyclopaedia of Genes and Genomes (KEGG) Pathway Database.

RESULTS

Nine studies met the inclusion criteria, reporting on 1117 patients. Increased metabolic activity in the urea cycle (p = 0.002, FDR = 0.198), ammonia recycling (p = 0.004, FDR = 0.359) and glycine and serine metabolism (p = 0.004, FDR = 0.374) was prognostic of CRC recurrence. Increased activity in aspartate metabolism (p < 0.001, FDR = 0.079) and ammonia recycling (p = 0.004, FDR = 0.345) was prognostic of survival. Eight resulting SNPs were prognostic for CRC recurrence (rs2194980, rs1392880, rs2567397, rs715, rs169712, rs2300701, rs313408, rs7018169) and three for survival (rs2194980, rs169712, rs12106698) of which two overlapped with recurrence (rs2194980, rs169712).

CONCLUSIONS

With a caveat on study heterogeneity, specific metabolites and metabolic pathway activity appear evident in the setting of poor prognostic colorectal cancers and such metabolic signatures are associated with specific genomic SNPs.

USP13 promotes development and metastasis of high-grade serous ovarian carcinoma in a novel mouse model

Epithelial ovarian cancer is the most lethal gynecologic malignancy and one of the most common causes of cancer mortality among women worldwide. Ubiquitin-Specific Peptidase 13 (USP13) gene copy is strongly amplified in human epithelial ovarian cancer, and high USP13 expression is correlated with poor survival outcomes. Yet, its pathological contribution to ovarian tumorigenesis remains unknown. We crossed a conditional Usp13 overexpressing knock-in mouse with a conditional knockout of Trp53 and Pten mouse and generated a novel ovarian cancer genetically engineered mouse model (GEMM), which closely recapitulates the genetic changes driving ovarian cancer in humans. Overexpression of USP13 with deletion of Trp53 and Pten in murine ovarian surface epithelium accelerated ovarian tumorigenesis and led to decreased survival in mice. Notably, USP13 greatly enhanced peritoneal metastasis of ovarian tumors with frequent development of hemorrhagic ascites. The primary and metastatic tumors exhibited morphology and clinical behavior similar to human high-grade serous ovarian cancer. Co-inhibition of USP13 and AKT significantly decreased the viability of the primary murine ovarian cancer cells isolated from the GEMM. USP13 also increased the tumorigenic and metastatic abilities of primary murine ovarian cancer cells in a syngeneic mouse study. These findings suggest a critical role of USP13 in ovarian cancer development and reveal USP13 as a potential therapeutic target for ovarian cancer.

Resistance to mutant KRASV12-induced senescence in a hTERT/Cdk4-immortalized normal human bronchial epithelial cell line

Mutant KRAS, the most frequently occurring (∼30%) driver oncogene in lung adenocarcinoma, induces normal epithelial cells to undergo senescence. This phenomenon, called "oncogene-induced senescence (OIS)", prevents mutant KRAS-induced malignant transformation. We have previously reported that mutant KRAS^V12 induces OIS in a subset of normal human bronchial epithelial cell line immortalized with hTERT and Cdk4. Understanding the mechanism and efficacy of this important cancer prevention mechanism is a key knowledge gap. Therefore, this study investigates mutant KRAS^V12-induced OIS in upregulated telomerase combined with the p16/RB pathway inactivation in normal bronchial epithelial cells. The normal (non-transformed and non-tumorigenic) human bronchial epithelial cell line HBEC3 (also called "HBEC3KT"), immortalized with hTERT ("T") and Cdk4 ("K"), was used in this study. HBEC3 that expressed mutant KRAS^V12 in a doxycycline-regulated manner was established (designated as HBEC3-RIN2). Controlled induction of mutant KRAS^V12 expression induced partial epithelial-to-mesenchymal transition in HBEC3-RIN2 cells, which was associated with upregulated expression of ZEB1 and SNAIL. Mutant KRAS^V12 caused the majority of HBEC3-RIN2 to undergo morphological changes; suggestive of senescence, which was associated with enhanced autophagic flux, evaluated by LC-3 Western blot and CYTO-ID, an autophagosome-specific staining kit. Upon mutant KRAS^V12 expression, only a small HBEC3-RIN2 cell subset underwent senescence, as shown by a senescence-associated β-galactosidase staining (SA-βG) method. Furthermore, mutant KRAS^V12 enhanced cell growth, evaluated by colorimetric proliferation assay, and liquid and soft agar colony formation assays, partially through increased phosphorylated AKT and ERK expression but did not affect cell division, or cell cycle status. Intriguingly, mutant KRAS^V12 reduced p53 protein expression but increased p21 protein expression by prolonging its half-life. These results indicate that a hTERT/Cdk4 -immortalized normal bronchial epithelial cell line is partially resistant to mutant KRAS^V12-induced senescence. This suggests that OIS does not efficiently suppress KRAS^V12-induced transformation in the context of the simultaneous occurrence of telomerase upregulation and inactivation of the p16/Rb pathway.

Targeting Oncogenic KRAS in Non-Small-Cell Lung Cancer

Simple Summary

v-Ki-ras2 Kirsten rat sarcoma viral oncogene (KRAS) is the most common driver in NSCLC, and targeting oncogenic KRAS is a major challenge in the treatment of non-small-cell lung cancer (NSCLC). While several covalent KRAS G12C inhibitors have emerged as a novel anti-KRAS therapy, the development of combined therapies involving the targeting of oncogenic KRAS plus other targeted drugs is still required given the vast heterogeneity of KRAS-mutated tumors. In this review, we summarize the biological and immunological characteristics of oncogenic KRAS-driven NSCLC and the preclinical and clinical evidence for mutant KRAS-targeted therapies. We also discuss the mechanisms of resistance to KRAS G12C inhibitors and possible therapeutic strategies to overcome this drug resistance.

Abstract

Recent advances in molecular biology and the resultant identification of driver oncogenes have achieved major progress in precision medicine for non-small-cell lung cancer (NSCLC). v-Ki-ras2 Kirsten rat sarcoma viral oncogene (KRAS) is the most common driver in NSCLC, and targeting KRAS is considerably important. The recent discovery of covalent KRAS G12C inhibitors offers hope for improving the prognosis of NSCLC patients, but the development of combination therapies corresponding to tumor characteristics is still required given the vast heterogeneity of KRAS-mutated NSCLC. In this review, we summarize the current understanding of KRAS mutations regarding the involvement of malignant transformation and describe the preclinical and clinical evidence for targeting KRAS-mutated NSCLC. We also discuss the mechanisms of resistance to KRAS G12C inhibitors and possible combination treatment strategies to overcome this drug resistance.

Upregulation of long noncoding RNA XIST has anticancer effects on ovarian cancer through sponging miR-106a

Ovarian cancer (OC) is a highly malignant tumor. X inactive specific transcript (XIST) was identified as a cancer-related gene, while its therapeutic effect in OC was poorly defined. The present study was designed to investigate the effectual corollary of the lncRNA XIST in OC. RT-qPCR was used to detect the XIST and miR-106a expression levels of OC tissues and cell lines. OC cell apoptosis and proliferation were detected by flow cytometry, colony formation, and CCK-8 assays. Moreover, bioinformatics analysis was used to predict the targeted miRNA of XIST. The dual-luciferase reporter and RNA pull-down assays were then used to verify the interaction between miR-106a and XIST. OC xenograft nude mice were raised to measure tumor growth. Notably, OC tissues and cells exhibited low XIST levels and high miR-106a levels. The XIST upregulation decreased the OVCAR3 and CAOV3 cell proliferation and inversely promoted cell apoptosis. miR-106a targeted the XIST. Also, the miR-106a overexpression reversed the inhibitory effects of XIST on OC cell proliferation and apoptosis. Our in vivo results suggested that XIST was involved in tumor growth deceleration, while the miR-106a reversed the effect. To conclusion, the present study demonstrated that XIST suppressed OC development via sponging miR-106a both in vitro and in vivo.

PTEN Protein Loss and Loss-of-Function Mutations in Gastric Cancers: The Relationship with Microsatellite Instability, EBV, HER2, and PD-L1 Expression

Inactivation of phosphatase and tensin homolog (PTEN) is caused by multiple mechanisms, and loss of PTEN activity is related to the progression of various cancers. In gastric cancer (GC), the relationship between the loss of PTEN protein expression and various genetic alterations remains unclear. The effects of microsatellite instability (MSI), Epstein–Barr virus (EBV), HER2 overexpression, and PD-L1 expression on PTEN mutation have not been fully explored. We performed comprehensive cancer panel tests with a cohort of 322 tumor samples from patients with advanced GC. Immunohistochemistry for PTEN protein was performed in all cases, and the loss of protein expression was defined as a complete absence of nuclear staining. In total, 34 cases (10.6%) had pathogenic PTEN mutations, of which 19 (55.9%) showed PTEN protein loss. The most common PTEN variants associated with protein loss were p.R130 (n = 4) followed by p.R335, p.L265fs, and deletions (n = 2). All the ten nonsense mutations identified in the samples resulted in PTEN inactivation. In the remaining 288 GC cases with wild-type PTEN, protein loss was found in 35 cases (12.2%). Thus, PTEN mutations were significantly associated with PTEN protein loss (p = 5.232 × 10⁻¹⁰), high MSI (p = 3.936 × 10⁻⁸), and EBV-positivity (p = 0.0071). In conclusion, our results demonstrate that loss-of-function mutations in PTEN are a frequent genetic mechanism of PTEN inactivation in GC.

PTEN and Gynecological Cancers

PTEN is a tumour suppressor gene, and its loss of function is frequently observed in both heritable and sporadic cancers. It is involved in a great variety of biological processes, including maintenance of genomic stability, cell survival, migration, proliferation and metabolism. A better understanding of PTEN activity and regulation has therefore emerged as a subject of primary interest in cancer research. Gynaecological cancers are variously interested by PTEN deregulation and many perspective in terms of additional prognostic information and new therapeutic approaches can be explored. Here, we present the most significant findings on PTEN in gynaecological cancers (ovarian, endometrial, cervical, vulvar and uterine cancer) focusing on PTEN alterations incidence, biological role and clinical implications.

Overexpression of RASAL1 Indicates Poor Prognosis and Promotes Invasion of Ovarian Cancer

RAS protein activator like-1 (RASAL1) exists in numerous human tissues and has been commonly demonstrated to act as a tumor suppressor in several cancers. This study aimed to identify the functional characteristics of RASAL1 in ovarian adenocarcinoma and a potential mechanism of action. We analyzed RASAL1 gene expression in ovarian adenocarcinoma samples and normal samples gained from the GEO and Oncomine databases respectively. Then the relationship between RASAL1 expression and overall survival (OS) was assessed using the Kaplan-Meier method. Furthermore, the biological effect of RASAL1 in ovarian adenocarcinoma cell lines was assessed by Quantitative real time-PCR (qRT-PCR), Cell Counting Kit-8 (CCK-8), western blot, wound healing and transwell assay. The statistical analysis showed patients with higher RASAL1 expression correlated with worse OS. The in vitro assays suggested knockdown of RASAL1 could inhibit cell proliferation, cell invasion and migration of ovarian adenocarcinoma. Moreover, the key proteins in the mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK/ERK) signaling pathway were also decreased in ovarian adenocarcinoma cells with RASAL1 silencing. These findings provide promising evidence that RASAL1 may be not only a powerful biomarker but also an effective therapeutic target of ovarian adenocarcinoma.

Single-cell RNA-sequencing reveals transcriptional dynamics of estrogen-induced dysplasia in the ovarian surface epithelium

Estrogen therapy increases the risk of ovarian cancer and exogenous estradiol accelerates the onset of ovarian cancer in mouse models. Both in vivo and in vitro, ovarian surface epithelial (OSE) cells exposed to estradiol develop a subpopulation that loses cell polarity, contact inhibition, and forms multi-layered foci of dysplastic cells with increased susceptibility to transformation. Here, we use single-cell RNA-sequencing to characterize this dysplastic subpopulation and identify the transcriptional dynamics involved in its emergence. Estradiol-treated cells were characterized by up-regulation of genes associated with proliferation, metabolism, and survival pathways. Pseudotemporal ordering revealed that OSE cells occupy a largely linear phenotypic spectrum that, in estradiol-treated cells, diverges towards cell state consistent with the dysplastic population. This divergence is characterized by the activation of various cancer-associated pathways including an increase in Greb1 which was validated in fallopian tube epithelium and human ovarian cancers. Taken together, this work reveals possible mechanisms by which estradiol increases epithelial cell susceptibility to tumour initiation.

Sialyltransferase ST3GAL1 promotes cell migration, invasion, and TGF-β1-induced EMT and confers paclitaxel resistance in ovarian cancer

Sialyltransferases transfer sialic acid to nascent oligosaccharides and are upregulated in cancer. The inhibition of sialyltransferases is emerging as a potential strategy to prevent metastasis in several cancers, including ovarian cancer. ST3GAL1 is a sialyltransferase that catalyzes the transfer of sialic acid from cytidine monophosphate-sialic acid to galactose-containing substrates and is associated with cancer progression and chemoresistance. However, the function of ST3GAL1 in ovarian cancer is uncertain. Herein, we use qRT-PCR, western blotting, and immunohistochemistry to assess the expression of ST3GAL1 in ovarian cancer tissue and cell lines and investigate whether it influences resistance to paclitaxel in vitro and in a mouse xenograft model. We found that ST3GAL1 is upregulated in ovarian cancer tissues and in the ovarian cancer cell lines SKOV-3 and OVCAR3 but downregulated in A2780 ovarian cancer cells. Overexpression of ST3GAL1 in A2780 cells increases cell growth, migration, and invasion whereas ST3GAL1 knockdown in SKOV-3 cells decreases cell growth, migration, and invasion. Furthermore, overexpression of ST3GAL1 increases resistance to paclitaxel while downregulation of ST3GAL1 decreases resistance to paclitaxel in vitro, and overexpression of ST3GAL1 increases tumorigenicity and resistance to paclitaxel in vivo. Transforming growth factor-β1 can increase ST3GAL1 expression and induce ovarian cell epithelial-mesenchymal transition (EMT). However, knockdown of ST3GAL1 inhibits EMT expression. Taken together, our findings have identified a regulatory mechanism involving ST3GAL1 in ovarian cancer. ST3GAL1 may be a promising target for overcoming paclitaxel resistance in ovarian carcinoma.

Epithelialization of mouse ovarian tumor cells originating in the fallopian tube stroma

Epithelial ovarian carcinoma accounts for 90% of all ovarian cancer and is the most deadly gynecologic malignancy. Recent studies have suggested that fallopian tube fimbriae can be the origin of cells for high-grade serous subtype of epithelial ovarian carcinoma (HGSOC). A mouse HGSOC model with conditional Dicer-Pten double knockout (Dicer-Pten DKO) developed primary tumors, intriguingly, from the fallopian tube stroma. We examined the growth and epithelial phenotypes of the Dicer-Pten DKO mouse tumor cells contributable by each gene knockout. Unlike human ovarian epithelial cancer cells that expressed full-length E-cadherin, the Dicer-Pten DKO stromal tumor cells expressed cleaved E-cadherin fragments and metalloproteinase 2, a mixture of epithelial and mesenchymal markers. Although the Dicer-Pten DKO tumor cells lost the expression of mature microRNAs as expected, they showed high levels of tRNA fragment expression and enhanced AKT activation due to the loss of PTEN function. Introduction of a Dicer1-expressing construct into the DKO mouse tumor cells significantly reduced DNA synthesis and the cell growth rate, with concurrent diminished adhesion and ZO1 epithelial staining. Hence, it is likely that the loss of Dicer promoted mesenchymal-epithelial transition in fallopian tube stromal cells, and in conjunction with Pten loss, further promoted cell proliferation and epithelial-like tumorigenesis.

Stearoyl-CoA desaturase-1 promotes colorectal cancer metastasis in response to glucose by suppressing PTEN

BACKGROUND

Diabetic patients have a higher risk factor for colorectal cancer (CRC) metastasis. Stearoyl-CoA desaturase 1 (SCD1), the main enzyme responsible for producing monounsaturated fatty acids(MUFA) from saturated fatty acids, is frequently deregulated in both diabetes and CRC. The function and mechanism of SCD1 in metastasis of CRC and its relevance to glucose remains largely unknown.

METHODS

SCD1 expression levels were analyzed in human CRC tissues and the Cancer Browser database ( https://genome-cancer.ucsc.edu/ ). CRC cell lines stably transfected with SCD1 shRNAs or vector were established to investigate the role of SCD1 in modulating migration and invasion of CRC cells. A glucose concentration gradient was set to investigate regulation of SCD1 in CRC relevant to diabetic conditions.

RESULTS

The clinical data analysis showed high expression of SCD1 in CRC tissues with a negative correlation with the prognosis of CRC. In vitro experiments revealed that SCD1 increased CRC progression through promoting epithelial-mesenchymal transition (EMT). Lipidomic analysis demonstrated that SCD1 increased MUFA levels and MUFA administration could rescue migration and invasion defect of CRC cells induced by SCD1 knockdown. Furthermore, SCD1-mediated progression of CRC was promoted by carbohydrate response-element binding protein (ChREBP) in response to high glucose. Mechanistically, hyperglycemia-SCD1-MUFA induced CRC cell migration and invasion by regulating PTEN.

CONCLUSIONS

Our findings show that SCD1 promotes metastasis of CRC cells through MUFA production and suppressing PTEN in response to glucose, which may be a novel mechanism for diabetes-induced CRC metastasis.

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.

Human endometrial stem cells: High-yield isolation and characterization

BACKGROUND

Menstrual blood is only recently and still poorly studied, but it is an abundant and noninvasive source of highly proliferative mesenchymal stromal cells (MSCs). However, no appropriate isolation method has been reported due to its high viscosity and high content of clots and desquamated epithelium.

METHODS

We studied three different isolation approaches and their combinations: ammonium-containing lysing buffer, distilled water and gradient-density centrifugation. We tested the proliferative capacity, morphology, surface markers and pluripotency of the resulting cells.

RESULTS

Our isolation method yields up to four million nucleated cells per milliliter of initial blood, of which about 0.2-0.3% are colony-forming cells expressing standard mesenchymal markers CD90, CD105 and CD73, but not expressing CD45, CD34, CD117, CD133 or HLA-G. The cells have high proliferative potential (doubling in 26 h) and the ability to differentiate into adipocytes and osteocytes. Early endometrial MSCs (eMSCs) express epithelial marker cytokeratin 7 (CK7). CK7 is easily induced in later passages in a prohepatic environment. We show for the first time that a satisfactory and stable yield of eMSCs is observed throughout the whole menstrual period (5 consecutive days) of a healthy woman.

DISCUSSION

The new cost/yield adequate method allows isolation from menstrual blood a relatively homogenous pool of highly proliferative MSCs, which seem to be the best candidates for internal organ therapy due to their proepithelial background (early expression of CK7 and its easy induction in later passages) and for mass cryobanking due to their high yield and availability.

PTEN loss in the fallopian tube induces hyperplasia and ovarian tumor formation

The signaling events involved in the onset of ovarian cancer from the fallopian tube epithelium (FTE) are crucial for early detection and treatment of the disease, but they remain poorly defined. Conditional homozygous knockout of PTEN mediated by PAX8-cre recombinase was sufficient to drive endometrioid and serous borderline ovarian carcinoma, providing the first model of FTE-derived borderline tumors. In addition, heterozygous PTEN deletion in the FTE resulted in hyperplasia, providing a model to study early events of human ovarian pathogenesis. To uncover the mechanism underlying the invasion of cancerous oviductal cells to the ovary, PTEN-deficient murine oviductal cells were developed and tagged with green fluorescent protein. Loss of PTEN increased cell migration, invasion, and upregulated WNT4, a key regulator of Müllerian duct development during embryogenesis. Further investigation revealed that WNT4 was required for increased migration and colonization of the ovary by PTEN-deficient oviductal cells in a β-catenin independent manner. Human tumor microarrays and ovarian cancer cells lines confirmed WNT4 expression in cancer and its role in migration. Together, these findings provide a novel model to study the mechanism of fallopian tube tumor initiation and invasion to the ovary mediated by loss of PTEN, which may help to define early events of human ovarian carcinogenesis.

Targeting epithelial-mesenchymal plasticity in cancer: clinical and preclinical advances in therapy and monitoring

The concept of epithelial-mesenchymal plasticity (EMP), which describes the dynamic flux within the spectrum of phenotypic states that invasive carcinoma cells may reside, is being increasingly recognised for its role in cancer progression and therapy resistance. The myriad of events that are able to induce EMP, as well as the more recently characterised control loops, results in dynamic transitions of cancerous epithelial cells to more mesenchymal-like phenotypes through an epithelial-mesenchymal transition (EMT), as well as the reverse transition from mesenchymal phenotypes to an epithelial one. The significance of EMP, in its ability to drive local invasion, generate cancer stem cells and facilitate metastasis by the dissemination of circulating tumour cells (CTCs), highlights its importance as a targetable programme to combat cancer morbidity and mortality. The focus of this review is to consolidate the existing knowledge on the strategies currently in development to combat cancer progression via inhibition of specific facets of EMP. The prevalence of relapse due to therapy resistance and metastatic propensity that EMP endows should be considered when designing therapy regimes, and such therapies should synergise with existing chemotherapeutics to benefit efficacy. To further improve upon EMP-targeted therapies, it is imperative to devise monitoring strategies to assess the impact of such treatments on EMP-related phenomenon such as CTC burden, chemosensitivity/-resistance and micrometastasis in patients.