Basic Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Oncol. Jun 24, 2019; 10(6): 222-233
Published online Jun 24, 2019. doi: 10.5306/wjco.v10.i6.222
Leptin-induced Notch and IL-1 signaling crosstalk in endometrial adenocarcinoma is associated with invasiveness and chemoresistance
Danielle Daley-Brown, Adriana Harbuzariu, Ann Anu Kurian, Gabriela Oprea-Ilies, Ruben Rene Gonzalez-Perez
Danielle Daley-Brown, Adriana Harbuzariu, Ann Anu Kurian, Ruben Rene Gonzalez-Perez, Department of Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, Atlanta, GA 30310, United States
Gabriela Oprea-Ilies, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322, United States
Author contributions: Daley-Brown D performed majority of experiments, compiled and interpreted data, and contributed to the preparation of the manuscript; Harbuzariu A developed cell cycle assays and contributed to data interpretation. Kurian AA helped with the development of western blots, cell cycle and cytotoxic analyses. Oprea-Ilies G provided guidance for interpretation of data and clinical pathology features. Gonzalez-Perez RR conceived the project, helped with the elaboration of the hypothesis, supervised the experimental work, and contributed to the interpretation of data and preparation of the manuscript.
Supported by the National Cancer Institute at the National Institutes of Health, No. S21 MD000101, No. 5G12 MD0076021, No. G12 RR026250-03, No. NIH RR03034 1C06, No. RR18386 to Morehouse School of Medicine; the National Institute of General Medical Sciences, National Institutes of Health, No. 5T32HL103104-04 to DDB.
Conflict-of-interest statement: The authors declare to have no conflict of interest.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Ruben Rene Gonzalez-Perez, PhD, Professor, Department of Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, Atlanta, GA 30310, United States. rgonzalez@msm.edu
Telephone: +1-404-7521581 Fax: +1-404-7521179
Received: September 7, 2018
Peer-review started: September 7, 2018
First decision: October 26, 2018
Revised: March 14, 2019
Accepted: March 27, 2019
Article in press: March 28, 2019
Published online: June 24, 2019
ARTICLE HIGHLIGHTS
Research background

The expression of Notch, Interleukin-1 (IL-1) and leptin outcome (NILCO) molecules (mRNAs and proteins) was previously detected in breast cancer and endometrial cancer (EmCa) from African-American and Chinese patients. Although, obesity status of Chinese patients was unknown, it looked like that NILCO was higher expressed in obese patients. However, NILCO molecules were expressed higher in type II EmCa, regardless of ethnic background or obesity status of patients. Leptin levels are high in obese patients that may suggest this adipokine is involved in the progression of the more aggressive EmCa phenotype (type II) and chemore-sistance.

Research motivation

EmCa is the most frequent gynecological malignancy of the female reproductive tract and is the fourth most commonly diagnosed new cancer among women in the United States. Hormone nonresponsive breast cancer and type II EmCa have no targeted therapies, are mainly treated with chemotherapeutics and eventually develop drug resistance. Because leptin is a known inducer of NILCO in breast cancer and has been related to chemoresistance, it was hypothesized that comparable leptin’s actions could occur in EmCa. The validation of this hypothesis may suggest that NILCO plays essential roles in tumor progression and chemoresistance, and thus, may represent a new EmCa target, particularly for type II EmCa.

Research objectives

To investigate whether leptin mediates the expression of NILCO signaling components, and impairs paclitaxel cytotoxic effects, and whether leptin’s proliferative, invasion and chemo-resistant actions are more prominent in type II EmCa cells.

Research methods

Two representative type I and type II (more aggressive and estrogen independent) EmCa cell lines were investigated for the potential leptin regulation of NILCO mRNA and proteins [Notch receptors, ligands and downstream effectors, and leptin (OB-R) and IL-1 (IL-1R tI) receptors] via Real-time PCR and Western blot analysis. Leptin’s proliferative and invasion effects were assessed by cytometric analysis (Cellometer Vision CBA system), and MTT and Matrigel-based invasion assays. NILCO inhibitors included nanoparticle-bound leptin peptide receptor antagonist-2 (IONP-LPrA2), anti-IL-1R tI antibody and Notch siRNA. The CCK8 assay was used to investigate leptin-mediated Paclitaxel drug resistance. Additionally, apoptotic and viable Paclitaxel-treated EmCa cells were determined by the Annexin V FITC/PI Assay (Nexcelom).

Research results

Leptin increased at least two-fold mRNA and protein levels of Notch receptors, ligands and downstream targets, and almost four-fold protein levels of OB-R and IL-1R tI in a dose dependent manner, mainly in type II EmCa cells. Leptin stimulated higher the progression of cell cycle, and the proliferation and invasion of type II EmCa cells, which were Notch-signaling dependent. The inhibition of IL-1R tI impaired the effects of leptin on Notch. Abrogation of Notch signaling via siRNA negatively affected leptin-induced EmCa invasiveness. Additionally, leptin acted as a survival factor for EmCa cells by significantly reducing the cytotoxic effects on Paclitaxel, which was more prominent in type II EmCa cells. The inhibition of OB-R via IONP-LPrA2 allowed the resensitization of EmCa cells to Paclitaxel. Thus, IONP-LPrA2 has a potential as a novel neo-adjuvant that may allow reducing Paclitaxel dosage and its undesirable side effects.

Research conclusions

For the first time, it was found that leptin is an inducer of Notch and targets in EmCa. Leptin-induced NILCO could be specifically related to the progression, invasiveness and drug resistance of type II EmCa. Moreover, obesity could increase the progression of EmCa and the development of chemoresistance via leptin signaling and NILCO, which may be greater for type II EmCa. Leptin-induces NILCO, which could be a common signaling crosstalk that stimulates the progression and chemoresistance of several obesity-related cancers. Present data suggest that NILCO plays essential roles in tumor progression and chemoresistance, and thus, may represent a new EmCa target, particularly for type II EmCa.

Research perspectives

In vitro data suggest that EmCa requires leptin signaling and NILCO for proliferation and invasion, and to increase drug resistance and survival. Future research should investigate the role of NILCO in EmCa progression and chemoresistance using animal models. Spontaneous, syngeneic, xenograft and PDX EmCa-mouse models should be used to validate the hypothesis tested in the present paper.