Synergistic effects of selective inhibitors targeting the PI3K/AKT/mTOR pathway or NUP214-ABL1 fusion protein in human Acute Lymphoblastic Leukemia

Pre-and post-HSCT use of TKI therapy for fusion-driven B-ALL: A case series of five pediatric, adolescent and young adult patients

BACKGROUND

The development of tyrosine kinase inhibitors (TKIs) has significantly improved survival rates among patients with Philadelphia chromosome (Ph+) B cell acute lymphoblastic leukemia (B-ALL). Ph-like B-ALL patients lack the BCR::ABL1 translocation but share gene expression profiles with Ph+ B-ALL. The role of TKIs for Ph-like patients pre- and post-hematopoietic stem cell transplantation (HSCT) is not yet clear.

CASE

Here we present five cases of pediatric, adolescent, and young adult patients who presented with Ph-like B-ALL or CML in B-ALL blast phase who were treated with personalized TKI regimens pre- and post-HSCT.

CONCLUSION

This report describes several novel Ph-like fusions as well as combinations of TKIs with chemotherapy or immunotherapy not yet reported in the pediatric population. This case series provides real-world experience highlighting the potential application of pre- and post-HSCT use of TKIs in a subset of patients with targetable fusions.

PI3K/Akt/mTOR Signaling Pathway in Blood Malignancies-New Therapeutic Possibilities

Blood malignancies remain a therapeutic challenge despite the development of numerous treatment strategies. The phosphatidylinositol-3 kinase (PI3K)/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway plays a central role in regulating many cellular functions, including cell cycle, proliferation, quiescence, and longevity. Therefore, dysregulation of this pathway is a characteristic feature of carcinogenesis. Increased activation of PI3K/Akt/mTOR signaling enhances proliferation, growth, and resistance to chemo- and immunotherapy in cancer cells. Overactivation of the pathway has been found in various types of cancer, including acute and chronic leukemia. Inhibitors of the PI3K/Akt/mTOR pathway have been used in leukemia treatment since 2014, and some of them have improved treatment outcomes in clinical trials. Recently, new inhibitors of PI3K/Akt/mTOR signaling have been developed and tested both in preclinical and clinical models. In this review, we outline the role of the PI3K/Akt/mTOR signaling pathway in blood malignancies' cells and gather information on the inhibitors of this pathway that might provide a novel therapeutic opportunity against leukemia.

The role of the mTOR pathway in diabetic retinopathy

The retina, the part of the eye, translates the light signal into an electric current that can be sent to the brain as visual information. To achieve this, the retina requires fine-tuned vascularization for its energy supply. Diabetic retinopathy (DR) causes alterations in the eye vascularization that reduce the oxygen supply with consequent retinal neurodegeneration. During DR, the mammalian target of rapamycin (mTOR) pathway seems to coordinate retinal neurodegeneration with multiple anabolic and catabolic processes, such as autophagy, oxidative stress, cell death, and the release of pro-inflammatory cytokines, which are closely related to chronic hyperglycemia. This review outlines the normal anatomy of the retina and how hyperglycemia can be involved in the neurodegeneration underlying this disease through over activation or inhibition of the mTOR pathway.

Developing therapeutic approaches for chronic myeloid leukemia: a review

Modern clinical therapy of chronic myeloid leukemia (CML) with TKIs is highly efficacious in most CML patients, while it is not remedial and generally confined due to intolerance or resistance. CML is currently considered a severe disease. Interestingly, stem cell transplantation in the past decade was an attractive clinical therapeutic option in CML patients, but it is not successful due to independently more death rates in older patients. So, the targeting of BCR::ABL oncoprotein is extensively used to enhance the reduction in a higher percentage of CML patients by tyrosine kinase inhibitors (TKIs). However, resistance or intolerance responses to these inhibitors are responsible for future deterioration and further development of disease. At this point, the clinical treatment of CML is a major challenge, and the lack of molecular responses to TKIs are not succeeded with chemotherapy alone. So, the considerable efficacious clinical necessities remain unmet. Therefore, continuous efforts are needed to explore new potential treatment strategies with an increasing understanding of CML biology. Therefore, this review deals with the investigation of TKI treatment with interferon, chemotherapy (Hydroxyurea, Homoharringtonine, Omacetaxine, Cytarabine), and several other new TKIs under beneficial clinical trials. Additionally, the approaches towards TKIs-resistant or intolerant CML cells where the respective signaling pathway gets up-regulated are also targeted with its inhibitor. This review presents evidence that new TKIs under clinical and pre-clinical trials may improve the chemotherapy of CML.

Seed oil of Brucea javanica induces apoptosis through the PI3K/Akt signaling pathway in acute lymphocytic leukemia Jurkat cells

Brucea javanica oil emulsion (BJOE) has been used to treat tumor in China for more than 40 years. However, its components and effectiveness in the treatment of acute lymphocytic leukemia (ALL) and its mechanism of anti-cancer activity remain unknown. In the current study, high-performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD) was used to analyze the components of BJOE. Then, the anti-leukemia effects of BJOE were examined both in vitro and in vivo using ALL Jurkat cells and the p388 mouse leukemia transplant model, respectively. The primary ALL leukemia cells were also used to confirm the anti-leukemia effects of BJOE. The apoptotic-related results indicated that BJOE induced apoptosis in Jurkat cells and were suggestive of intrinsic apoptotic induction. Moreover, BJOE inhibited Akt (protein kinase B) activation and upregulated its downstream targets p53 and FoxO1 (forkhead box gene, group O-1) to initiate apoptosis. The activation of GSK3β was also involved. Our findings demonstrate that BJOE has anti-leukemia effects on ALL cells and can induce apoptosis in Jurkat cells through the phosphoinositide3-kinase (PI3K) /Akt signaling pathway.

Role of Autophagy and Apoptosis in Acute Lymphoblastic Leukemia

Background:

Acute lymphoblastic leukemia (ALL) is a malignant disease characterized by an excessive number of immature lymphocytes, including immature precursors of both B- and T cells. ALL affects children more often than adults. Immature lymphocytes lead to arrested differentiation and proliferation of cells. Its conventional treatments involve medication with dexamethasone, vincristine, and other anticancer drugs. Although the current first-line drugs can achieve effective treatment, they still cannot prevent the recurrence of some patients with ALL. Treatments have high risk of recurrence especially after the first remission. Currently, novel therapies to treat ALL are in need. Autophagy and apoptosis play important roles in regulating cancer development. Autophagy involves degradation of proteins and organelles, and apoptosis leads to cell death. These phenomena are crucial in cancer progression. Past studies reported that many potential anticancer agents regulate intracellular signaling pathways.

Methods:

The authors discuss the recent research findings on the role of autophagy and apoptosis in ALL.

Results:

The autophagy and apoptosis are widely used in the treatment of ALL. Most studies showed that many agents regulate autophagy and apoptosis in ALL cell models, clinical trials, and ALL animal models.

Conclusions:

In summary, activating autophagy and apoptosis pathways are the main strategies for ALL treatments. For ALL, combining new drugs with traditional chemotherapy and glucocorticoids treatments can achieve the greatest therapeutic effect by activating autophagy and apoptosis.

Combating TKI resistance in CML by inhibiting the PI3K/Akt/mTOR pathway in combination with TKIs: a review

Chronic myeloid leukemia (CML), a myeloproliferative hematopoietic cancer, is caused by a genetic translocation between chromosomes 9 and 22. This translocation produces a small Philadelphia chromosome, which contains the Bcr-Abl oncogene. The Bcr-Abl oncogene encodes the BCR-ABL protein, upregulates various signaling pathways (JAK-STAT, MAPK/ERK, and PI3K/Akt/mTOR), and out of which the specifically highly active pathway is the PI3K/Akt/mTOR pathway. Among early treatments for CML, tyrosine kinase inhibitors (TKIs) were found to be the most effective, but drug resistance against kinase inhibitors led to the discovery of novel alternative therapies. At this point, the PI3K/Akt/mTOR pathway components became new targets due to stimulation of this pathway in TKIs-resistant CML patients. The current review article deals with reviewing the scientific literature on the PI3K/Akt/mTOR pathway inhibitors listed in the National Cancer Institute (NCI) drug dictionary and proved effective against multiple cancers. And out of those enlisted inhibitors, the US FDA has also approved some PI3K inhibitors (Idelalisib, Copanlisib, and Duvelisib) and mTOR inhibitors (Everolimus, Sirolimus, and Temsirolimus) for cancer therapy. So far, several inhibitors have been tested, and further investigations are still ongoing. Even in Imatinib, Nilotinib, and Ponatinib-resistant CML cells, a dual PI3K/mTOR inhibitor, BEZ235, showed antiproliferative activity. Therefore, by considering the literature data of these reviews and further examining some of the reported inhibitors, which proved effective against the PI3K/Akt/mTOR signaling pathway in multiple cancers, may improve the therapeutic approaches towards TKI-resistant CML cells where the respective signaling pathway gets upregulated.

Growth inhibition and suppression of the mTOR and Wnt/β-catenin pathways in T-acute lymphoblastic leukemia by rapamycin and MYCN depletion

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy. Understanding of the molecular pathogenesis may lead to novel therapeutic targets. Rapamycin, the mammalian target of rapamycin (mTOR) inhibitor, showed inhibitory effects on T-ALL cells. In this study, we showed that rapamycin significantly reduced MYCN mRNA and protein in a concentration-dependent manner in T-ALL cells. Selective knockdown of MYCN by small interfering RNA had similar effects to rapamycin to inhibit T-ALL proliferation and colony formation and to induce G1-phase cell-cycle arrest and apoptosis. The inhibitory effects of rapamycin and MYCN depletion were also found in a Molt-4 xenograft model. Rapamycin and MYCN inhibition suppressed both Wnt/β-catenin and mTOR signaling pathways. The results suggest the effects of rapamycin on adult T-ALL is likely mediated by downregulation of MYCN. The findings suggest MYCN a potential target for the treatment of adult T-ALL. Additionally, dual targeting of mTOR and Wnt/β-catenin pathways may represent a novel strategy in the treatment of adult T-ALL.

Construction of a prognostic model based on nine immune-related genes and identification of small molecule drugs for hepatocellular carcinoma (HCC)

This study aimed to develop a prognostic model for hepatocellular carcinoma (HCC) based on immune-related genes and to identify new potential small-molecule drugs. A differential gene expression analysis of high-throughput microarray data from The Cancer Genome Atlas (TCGA) was performed to identify immune-related genes. By comparison with an immune-related genome, nine genes with important prognostic value for HCC were identified. The prognostic characteristics were established based on univariate and multivariate COX and Lasso regression analyzes. Subsequently, immune-related HCC risk signatures were constructed based on these identified nine immune-related genes and patients were classified as being at high or low risk according to these signatures. The overall survival (OS) time of high-risk patients was significantly shorter than that of low-risk patients. When studied as an independent prognostic factor of HCC, the significant prognostic value of this feature can be seen in the stratified cohorts. For clinical application, it was developed a nomogram that includes nine clinical risk factors and the prognostic model built based on the identified immune-related genes. Internal and external verification on 243 HCC tissues through International Cancer Genome Consortium (ICGC) database were performed to make this model more accurate and reliable. In addition, it was observed a positive regulation between the identified immune-related genes and their transcription factors found in HCC patients. Moreover, physiological function and signaling pathway of identified immune-related genes were studied by GO and KEGG enrichment analysis. Finally, several new small molecular drugs with potential for the treatment of HCC have been identified in the CMap database.

New biomarkers and therapeutic strategies in acute lymphoblastic leukemias: Recent advances

Acute lymphoblastic leukemia (ALL) represents a heterogeneous group of hematologic malignancies, and it is normally characterized by an aberrant proliferation of immature lymphoid cells. Moreover, dysregulation of multiple signaling pathways that normally regulate cellular transcription, growth, translation, and proliferation is frequently encountered in this malignancy. ALL is the most frequent tumor in childhood, and adult ALL patients still correlate with poor survival. This review focuses on modern therapies in ALL that move beyond standard chemotherapy, with a particular emphasis on immunotherapeutic approaches as new treatment strategies. Bi-specific T-cell Engagers (BiTE) antibodies, the chimeric antigen receptor (CAR)-T cells, or CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats [CRISPR]-associated nuclease 9) represent other new innovative approaches for this disease. Target and tailored therapy could make the difference in previously untreatable cases, i.e., precision and personalized medicine. Clinical trials will help to select the most efficient novel therapies in ALL management and to integrate them with existing treatments to achieve durable cures.

Notch/CXCR4 Partnership in Acute Lymphoblastic Leukemia Progression

Acute lymphoblastic leukemia (ALL) is the most common cancer among children. Recent advances in chemotherapy have made ALL a curable hematological malignancy. In children, there is 25% chance of disease relapse, typically in the central nervous system. While in adults, there is a higher chance of relapse. ALL may affect B-cell or T-cell lineages. Different genetic alterations characterize the two ALL forms. Deregulated Notch, either Notch1 or Notch3, and CXCR4 receptor signaling are involved in ALL disease development and progression. By analyzing their relevant roles in the pathogenesis of the two ALL forms, new molecular mechanisms able to modulate cancer cell invasion may be visualized. Notably, the partnership between Notch and CXCR4 may have considerable implications in understanding the complexity of T- and B-ALL. These two receptor pathways intersect other critical signals in the proliferative, differentiation, and metabolic programs of lymphocyte transformation. Also, the identification of the crosstalks in leukemia-stroma interaction within the tumor microenvironment may unveil new targetable mechanisms in disease relapse. Further studies are required to identify new challenges and opportunities to develop more selective and safer therapeutic strategies in ALL progression, possibly contributing to improve conventional hematological cancer therapy.

Identification and validation of an individualized autophagy-clinical prognostic index in bladder cancer patients

Purpose: Autophagy is a major catabolic system by which eukaryotic cells undergo self-degradation of damaged, defective, or unwanted intracellular components. An abnormal autophagic level is implicated in the pathogenesis of multiple diseases, including cancers. The aim of this study is to explore the prognostic value of autophagy in bladder cancer (BC), which is a major cause of cancer-related death globally.

Patients and methods: First, 27 differentially expressed autophagy-related genes (ARGs) were identified in BC patients based on The Cancer Genome Atlas (TCGA) database. Functional enrichment analyses hinted that autophagy may act in a tumor-suppressive role in the initiation of BC. Then, the Cox proportional hazard regression model were employed to identify three key prognostic ARGs (JUN, MYC, and ITGA3), which were related with overall survival (OS) significantly in BC. The three genes represented important clinical significance and prognostic value in BC. Then a prognostic index (PI) was constructed.

Results: The PI was constructed based on the three genes, and significantly stratified BC patients into high- and low-risk groups in terms of OS (HR=1.610, 95% CI=1.200–2.160, P=0.002). PI remained as an independent prognostic factor in multivariate analyses (HR=2.355, 95% CI=1.483–3.739, P<0.001). When integrated with clinical characteristics of age and stage, an autophagy-clinical prognostic index (ACPI) was finally validated, which had improved performance in predicting OS of BC patients (HR=2.669, 95% CI=1.986–3.587, P<0.001). The ACPI was confirmed in datasets of GSE13507 (HR=7.389, 95% CI=3.645–14.980, P<0.001) and GSE31684 (HR=1.665, 95% CI=0.872–3.179, P=0.122).

Conclusion: This study provides a potential prognostic signature for predicting prognosis of BC patients and molecular insights of autophagy in BC.

Detection of a cryptic NUP214/ABL1 gene fusion by mate-pair sequencing (MPseq) in a newly diagnosed case of pediatric T-lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematopoietic neoplasm involving the bone marrow and blood that accounts for ∼15% of childhood and 25% of adult ALL. Whereas multiple, recurrent genetic abnormalities have been described in T-ALL, their clinical significance is unclear or controversial. Importantly, ABL1 rearrangements, most commonly described in BCR/ABL1-positive B-ALL and BCR-ABL1-like B-ALL, have been observed in T-ALL and may respond to tyrosine kinase inhibitor (TKI) therapy. We describe a newly diagnosed case of pediatric T-ALL with a fluorescence in situ hybridization abnormality suggesting a partial ABL1 deletion by a BCR/ABL1 dual-color dual-fusion probe but that demonstrated a normal result using an ABL1 break-apart probe. Mate-pair sequencing (MPseq), a next-generation sequencing (NGS)-based technology utilized to detect copy number and structural abnormalities with high resolution and precision throughout the genome, was performed and revealed a NUP214/ABL1 gene fusion that has been demonstrated to be sensitive to TKI therapy. This case demonstrates the power of MPseq to resolve chromosomal abnormalities unappreciable by traditional cytogenetic methodologies and highlights the clinical value of this novel NGS-based technology.

Targeting mTOR in Acute Lymphoblastic Leukemia

Acute Lymphoblastic Leukemia (ALL) is an aggressive hematologic disorder and constitutes approximately 25% of cancer diagnoses among children and teenagers. Pediatric patients have a favourable prognosis, with 5-years overall survival rates near 90%, while adult ALL still correlates with poorer survival. However, during the past few decades, the therapeutic outcome of adult ALL was significantly ameliorated, mainly due to intensive pediatric-based protocols of chemotherapy. Mammalian (or mechanistic) target of rapamycin (mTOR) is a conserved serine/threonine kinase belonging to the phosphatidylinositol 3-kinase (PI3K)-related kinase family (PIKK) and resides in two distinct signalling complexes named mTORC1, involved in mRNA translation and protein synthesis and mTORC2 that controls cell survival and migration. Moreover, both complexes are remarkably involved in metabolism regulation. Growing evidence reports that mTOR dysregulation is related to metastatic potential, cell proliferation and angiogenesis and given that PI3K/Akt/mTOR network activation is often associated with poor prognosis and chemoresistance in ALL, there is a constant need to discover novel inhibitors for ALL treatment. Here, the current knowledge of mTOR signalling and the development of anti-mTOR compounds are documented, reporting the most relevant results from both preclinical and clinical studies in ALL that have contributed significantly into their efficacy or failure.

An integrated transcriptome analysis in T-cell acute lymphoblastic leukemia links DNA methylation subgroups to dysregulated TAL1 and ANTP homeobox gene expression

Classification of pediatric T‐cell acute lymphoblastic leukemia (T‐ALL) patients into CIMP (CpG Island Methylator Phenotype) subgroups has the potential to improve current risk stratification. To investigate the biology behind these CIMP subgroups, diagnostic samples from Nordic pediatric T‐ALL patients were characterized by genome‐wide methylation arrays, followed by targeted exome sequencing, telomere length measurement, and RNA sequencing. The CIMP subgroups did not correlate significantly with variations in epigenetic regulators. However, the CIMP+ subgroup, associated with better prognosis, showed indicators of longer replicative history, including shorter telomere length (P = 0.015) and older epigenetic (P < 0.001) and mitotic age (P < 0.001). Moreover, the CIMP+ subgroup had significantly higher expression of ANTP homeobox oncogenes, namely TLX3, HOXA9, HOXA10, and NKX2‐1, and novel genes in T‐ALL biology including PLCB4, PLXND1, and MYO18B. The CIMP− subgroup, with worse prognosis, was associated with higher expression of TAL1 along with frequent STIL‐TAL1 fusions (2/40 in CIMP+ vs 11/24 in CIMP−), as well as stronger expression of BEX1. Altogether, our findings suggest different routes for leukemogenic transformation in the T‐ALL CIMP subgroups, indicated by different replicative histories and distinct methylomic and transcriptomic profiles. These novel findings can lead to new therapeutic strategies.

HIF-1α and mTOR - Possible Novel Strategies of Targeted Therapies in p16-positive and -negative HNSCC

BACKGROUND/AIM

Targeted therapy in head and neck squamous cell carcinoma (HNSCC) is limited. HIF-1α and mTOR are involved in the formation of local tumor progression and distant metastasis. The present study analyzed the influence of well-established tyrosine kinase inhibitors nilotinib, dasatinib, erlotinib and gefitinib on the expression of HIF-1α and mTOR in p16-positive and -negative squamous cancer cells (SCC) in vitro in order to develop novel strategies in the treatment of HNSCC.

MATERIALS AND METHODS

Expression of HIF-1α and mTOR was analyzed by using Sandwich-ELISA in p16-negative and p16-positive SCC after treatment with nilotinib, dasatinib, erlotinib and gefitinib (20 μmol/l, 24-96 h of incubation).

RESULTS

All substances significantly reduced mTOR expression in both, p16-negative and p16-positive SCC (p<0.05). HIF-1α expression was significantly reduced by all tested substances in p16-negative SCC. However, a statistically significant increase of HIF-1α was observed in p16-positive SCC.

CONCLUSION

This is the first study to investigate the alteration of expression levels of HIF-1α and mTOR under selective tyrosine kinase inhibition in both p16-positive and -negative SCC. Our findings provide novel insights for a better understanding of HIF-1α and mTOR in the tumor biology of HNSCC and their interaction with selective small-molecule inhibitors.

New Challenges in Targeting Signaling Pathways in Acute Lymphoblastic Leukemia by NGS Approaches: An Update

The identification and study of genetic alterations involved in various signaling pathways associated with the pathogenesis of acute lymphoblastic leukemia (ALL) and the application of recent next-generation sequencing (NGS) in the identification of these lesions not only broaden our understanding of the involvement of various genetic alterations in the pathogenesis of the disease but also identify new therapeutic targets for future clinical trials. The present review describes the main deletions, amplifications, sequence mutations, epigenetic lesions, and new structural DNA rearrangements detected by NGS in B-ALL and T-ALL and their clinical importance for therapeutic procedures. We reviewed the molecular basis of pathways including transcriptional regulation, lymphoid differentiation and development, TP53 and the cell cycle, RAS signaling, JAK/STAT, NOTCH, PI3K/AKT/mTOR, Wnt/β-catenin signaling, chromatin structure modifiers, and epigenetic regulators. The implementation of NGS strategies has enabled important mutated genes in each pathway, their associations with the genetic subtypes of ALL, and their outcomes, which will be described further. We also discuss classic and new cryptic DNA rearrangements in ALL identified by mRNA-seq strategies. Novel cooperative abnormalities in ALL could be key prognostic and/or predictive biomarkers for selecting the best frontline treatment and for developing therapies after the first relapse or refractory disease.

The combination of digoxin and GSK2606414 exerts synergistic anticancer activity against leukemia in vitro and in vivo

Digoxin is a member of cardiac glycosides and recent studies show that digoxin plays anticancer role in several types of cancer. However, the anticancer effects and mechanism of digoxin in leukemia is largely unknown. Her, our data show that digoxin treatment significantly inhibits leukemia cell viability. In addition, digoxin treatment significantly induced apoptosis and G2/M cell cycle arrest in leukemia cells. Furthermore, we demonstrated that digoxin treatment inactivate that oncogenic pathway Akt/mTOR signaling in leukemia cells. In addition, our data show that digoxin treatment induces activation of unfolded protein response (UPR) signaling in leukemia cells. Interestingly, our in vitro and in vivo experiments show that combination treatment of digoxin and UPR inhibitor can synergistically suppress leukemia growth and induces apoptosis and cell cycle arrest compared to single drug treatment. In summary, our findings indicate that digoxin has potential anticancer effects on leukemia. The combination of digoxin and UPR signaling inhibitor can exerts synergistic anticancer activity against leukemia. © 2017 BioFactors, 43(6):812-820, 2017.

STYK1 promotes Warburg effect through PI3K/AKT signaling and predicts a poor prognosis in nasopharyngeal carcinoma

STYK1 (Serine/threonine/tyrosine kinase 1), a member of the receptor tyrosine kinase family, exhibits tumorigenicity in many types of cancers. Our study reveals the important role played by STYK1 in nasopharyngeal carcinoma. STYK1 is upregulated in nasopharyngeal carcinoma tissues compared with para-carcinoma. Knockdown of STYK1 inhibits nasopharyngeal carcinoma cell proliferation, migration, and invasion, while ectopic STYK1 expression significantly promoted cell proliferation, migration, and invasion abilities. In addition, we provided lines of evidence supporting the critical role of STYK1 in the regulation of glycolysis via activation of phosphoinositide 3-kinase/AKT pathway. Survival analysis reveals that STYK1 level is an independent prognostic factor for nasopharyngeal carcinoma patients. Our results indicate that STYK1 is a promising therapeutic target in nasopharyngeal carcinoma.

Differential expression of EWI-2 in endometriosis, its functional role and underlying molecular mechanisms

AIM

We aimed to investigate EWI-2 expression in endometrium tissues collected from women with endometriosis at mRNA and protein levels, to evaluate its potential as a biomarker for endometriosis and to study its functional role via possible regulation of the PI3K/Akt signaling pathway.

METHODS

Endometrium tissues were collected from patients with endometriosis and healthy individuals. EWI-2 mRNA expression was evaluated using quantitative real-time PCR (qRT-PCR) while EWI-2 protein levels were determined by western blotting. For functional studies, EWI-2 shRNA was transfected in endometrial epithelial cells and the in vitro migration and invasion assays were performed using the Transwell chambers.

RESULTS

EWI-2 was significantly downregulated in tissues obtained from patients with endometriosis compared with healthy individuals (P < 0.0001). EWI-2 expression in the secretory phase was lower than that in the proliferative phase (P < 0.0001). Receiver-operator curve analysis of EWI-2 expression showed that the area under the curve for endometriosis diagnosis was 0.8942 (P = 0.003), 0.9643 (P = 0.0001), 0.9912 (P < 0.0001), and 0.9150 (P < 0.0001), respectively, for healthy women compared with women with endometriosis in matched comparisons of data originated from the proliferative, early, middle, and late secretory phases. Over the menstrual cycle, the expression of EWI-2 was significantly decreased in the eutopic tissues compared to the ectopic tissues. Further cellular and molecular analyses showed that EWI-2 inhibited cell migration and invasion via the Akt signaling.

CONCLUSION

Our findings suggested that downregulation of EWI-2 may contribute to endometriosis physiopathology and potentiate EWI-2 as a valuable diagnostic biomarker and therapeutic target for endometriosis.