1
|
Chhichholiya Y, Suryan AK, Suman P, Munshi A, Singh S. SNPs in miRNAs and Target Sequences: Role in Cancer and Diabetes. Front Genet 2021; 12:793523. [PMID: 34925466 PMCID: PMC8673831 DOI: 10.3389/fgene.2021.793523] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 10/28/2021] [Indexed: 12/27/2022] Open
Abstract
miRNAs are fascinating molecular players for gene regulation as individual miRNA can control multiple targets and a single target can be regulated by multiple miRNAs. Loss of miRNA regulated gene expression is often reported to be implicated in various human diseases like diabetes and cancer. Recently, geneticists across the world started reporting single nucleotide polymorphism (SNPs) in seed sequences of miRNAs. Similarly, SNPs are also reported in various target sequences of these miRNAs. Both the scenarios lead to dysregulated gene expression which may result in the progression of diseases. In the present paper, we explore SNPs in various miRNAs and their target sequences reported in various human cancers as well as diabetes. Similarly, we also present evidence of these mutations in various other human diseases.
Collapse
Affiliation(s)
- Yogita Chhichholiya
- Department of Human Genetics and Molecular Medicine, Central University of Punjab, Bathinda, India
| | - Aman Kumar Suryan
- Department of Human Genetics and Molecular Medicine, Central University of Punjab, Bathinda, India
| | - Prabhat Suman
- Department of Human Genetics and Molecular Medicine, Central University of Punjab, Bathinda, India
| | - Anjana Munshi
- Department of Human Genetics and Molecular Medicine, Central University of Punjab, Bathinda, India
| | - Sandeep Singh
- Department of Human Genetics and Molecular Medicine, Central University of Punjab, Bathinda, India
| |
Collapse
|
2
|
Portman N, Chen J, Lim E. MDM2 as a Rational Target for Intervention in CDK4/6 Inhibitor Resistant, Hormone Receptor Positive Breast Cancer. Front Oncol 2021; 11:777867. [PMID: 34804982 PMCID: PMC8596371 DOI: 10.3389/fonc.2021.777867] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 10/19/2021] [Indexed: 11/13/2022] Open
Abstract
With the adoption of inhibitors of cyclin dependent kinases 4 and 6 (CDK4/6i) in combination with endocrine therapy as standard of care for the treatment of advanced and metastatic estrogen receptor positive (ER+) breast cancer, the search is now on for novel therapeutic options to manage the disease after the inevitable development of resistance to CDK4/6i. In this review we will consider the integral role that the p53/MDM2 axis plays in the interactions between CDK4/6, ERα, and inhibitors of these molecules, the current preclinical evidence for the efficacy of MDM2 inhibitors in ER+ breast cancer, and discuss the possibility of targeting the p53/MDM2 via inhibition of MDM2 in the CDK4/6i resistance setting.
Collapse
Affiliation(s)
- Neil Portman
- Cancer Theme, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.,St. Vincent's Clinical School, University of New South Wales (UNSW) Sydney, Kensington, NSW, Australia
| | - Julia Chen
- Cancer Theme, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.,St. Vincent's Clinical School, University of New South Wales (UNSW) Sydney, Kensington, NSW, Australia
| | - Elgene Lim
- Cancer Theme, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.,St. Vincent's Clinical School, University of New South Wales (UNSW) Sydney, Kensington, NSW, Australia
| |
Collapse
|
3
|
Abstract
Cancer is a complex disease with a high rate of mortality. The characteristics of tumor masses are very heterogeneous; thus, the appropriate classification of tumors is a critical point in the effective treatment. A high level of heterogeneity has also been observed in breast cancer. Therefore, detecting the molecular subtypes of this disease is an essential issue for medicine that could be facilitated using bioinformatics. This study aims to discover the molecular subtypes of breast cancer using somatic mutation profiles of tumors. Nonetheless, the somatic mutation profiles are very sparse. Therefore, a network propagation method is used in the gene interaction network to make the mutation profiles dense. Afterward, the deep embedded clustering (DEC) method is used to classify the breast tumors into four subtypes. In the next step, gene signature of each subtype is obtained using Fisher's exact test. Besides the enrichment of gene signatures in numerous biological databases, clinical and molecular analyses verify that the proposed method using mutation profiles can efficiently detect the molecular subtypes of breast cancer. Finally, a supervised classifier is trained based on the discovered subtypes to predict the molecular subtype of a new patient. The code and material of the method are available at: https://github.com/nrohani/MolecularSubtypes.
Collapse
Affiliation(s)
- Narjes Rohani
- Department of Computer and Data Sciences, Faculty of Mathematics, Shahid Beheshti University, Tehran, Iran
| | - Changiz Eslahchi
- Department of Computer and Data Sciences, Faculty of Mathematics, Shahid Beheshti University, Tehran, Iran.,School of Biological Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
| |
Collapse
|
4
|
Swetzig WM, Wang J, Das GM. Estrogen receptor alpha (ERα/ESR1) mediates the p53-independent overexpression of MDM4/MDMX and MDM2 in human breast cancer. Oncotarget 2017; 7:16049-69. [PMID: 26909605 PMCID: PMC4941297 DOI: 10.18632/oncotarget.7533] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 01/27/2016] [Indexed: 12/31/2022] Open
Abstract
MDM2 and MDM4 are heterodimeric, non-redundant oncoproteins that potently inhibit the p53 tumor suppressor protein. MDM2 and MDM4 also enhance the tumorigenicity of breast cancer cells in in vitro and in vivo models and are overexpressed in primary human breast cancers. Prior studies have characterized Estrogen Receptor Alpha (ERα/ESR1) as a regulator of MDM2 expression and an MDM2- and p53-interacting protein. However, similar crosstalk between ERα and MDM4 has not been investigated. Moreover, signaling pathways that mediate the overexpression of MDM4 in human breast cancer remain to be elucidated. Using the Cancer Genome Atlas (TCGA) breast invasive carcinoma patient cohort, we have analyzed correlations between ERα status and MDM4 and MDM2 expression in primary, treatment-naïve, invasive breast carcinoma samples. We report that the expression of MDM4 and MDM2 is elevated in primary human breast cancers of luminal A/B subtypes and associates with ERα-positive disease, independently of p53 mutation status. Furthermore, in cell culture models, ERα positively regulates MDM4 and MDM2 expression via p53-independent mechanisms, and these effects can be blocked by the clinically-relevant endocrine therapies fulvestrant and tamoxifen. Additionally, ERα also positively regulates p53 expression. Lastly, we report that endogenous MDM4 negatively regulates ERα expression and forms a protein complex with ERα in breast cancer cell lines and primary human breast tumor tissue. This suggests direct signaling crosstalk and negative feedback loops between ERα and MDM4 expression in breast cancer cells. Collectively, these novel findings implicate ERα as a central component of the p53-MDM2-MDM4 signaling axis in human breast cancer.
Collapse
Affiliation(s)
- Wendy M Swetzig
- Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY, USA.,Department of Molecular Pharmacology and Cancer Therapeutics, The University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Jianmin Wang
- Department of Bioinformatics and Biostatistics, Roswell Park Cancer Institute, Buffalo, NY, USA
| | - Gokul M Das
- Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY, USA.,Department of Molecular Pharmacology and Cancer Therapeutics, The University at Buffalo, State University of New York, Buffalo, NY, USA
| |
Collapse
|
5
|
Haupt S, Buckley D, Pang JMB, Panimaya J, Paul PJ, Gamell C, Takano EA, Lee YY, Hiddingh S, Rogers TM, Teunisse AFAS, Herold MJ, Marine JC, Fox SB, Jochemsen A, Haupt Y. Targeting Mdmx to treat breast cancers with wild-type p53. Cell Death Dis 2015; 6:e1821. [PMID: 26181202 PMCID: PMC4650725 DOI: 10.1038/cddis.2015.173] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 05/15/2015] [Accepted: 05/22/2015] [Indexed: 01/07/2023]
Abstract
The function of the tumor suppressor p53 is universally compromised in cancers. It is the most frequently mutated gene in human cancers (reviewed). In cases where p53 is not mutated, alternative regulatory pathways inactivate its tumor suppressive functions. This is primarily achieved through elevation in the expression of the key inhibitors of p53: Mdm2 or Mdmx (also called Mdm4) (reviewed). In breast cancer (BrCa), the frequency of p53 mutations varies markedly between the different subtypes, with basal-like BrCas bearing a high frequency of p53 mutations, whereas luminal BrCas generally express wild-type (wt) p53. Here we show that Mdmx is unexpectedly highly expressed in normal breast epithelial cells and its expression is further elevated in most luminal BrCas, whereas p53 expression is generally low, consistent with wt p53 status. Inducible knockdown (KD) of Mdmx in luminal BrCa MCF-7 cells impedes the growth of these cells in culture, in a p53-dependent manner. Importantly, KD of Mdmx in orthotopic xenograft transplants resulted in growth inhibition associated with prolonged survival, both in a preventative model and also in a treatment model. Growth impediment in response to Mdmx KD was associated with cellular senescence. The growth inhibitory capacity of Mdmx KD was recapitulated in an additional luminal BrCa cell line MPE600, which expresses wt p53. Further, the growth inhibitory capacity of Mdmx KD was also demonstrated in the wt p53 basal-like cell line SKBR7 line. These results identify Mdmx growth dependency in wt p53 expressing BrCas, across a range of subtypes. Based on our findings, we propose that Mdmx targeting is an attractive strategy for treating BrCas harboring wt p53.
Collapse
Affiliation(s)
- S Haupt
- Tumor Suppression Laboratory, Research Division, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - D Buckley
- Tumor Suppression Laboratory, Research Division, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - J-M B Pang
- Department of Pathology, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - J Panimaya
- Tumor Suppression Laboratory, Research Division, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - P J Paul
- Tumor Suppression Laboratory, Research Division, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - C Gamell
- Tumor Suppression Laboratory, Research Division, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - E A Takano
- Department of Pathology, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Y Ying Lee
- Tumor Suppression Laboratory, Research Division, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - S Hiddingh
- Tumor Suppression Laboratory, Research Division, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - T-M Rogers
- Department of Pathology, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - A F A S Teunisse
- Department of Molecular Cell Biology, University Medical Centre, Leiden, The Netherlands
| | - M J Herold
- 1] Department of Molecular Genetics of Cancer, The Walter and Eliza Hall Institute, Parkville, Victoria, Australia [2] Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - J-C Marine
- Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - S B Fox
- 1] Department of Pathology, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia [2] Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria, Australia
| | - A Jochemsen
- Department of Molecular Cell Biology, University Medical Centre, Leiden, The Netherlands
| | - Y Haupt
- 1] Tumor Suppression Laboratory, Research Division, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia [2] Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria, Australia [3] Department of Pathology, University of Melbourne, Parkville, Victoria, Australia [4] Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| |
Collapse
|
6
|
Park HS, Park JM, Park S, Cho J, Kim SI, Park BW. Subcellular localization of Mdm2 expression and prognosis of breast cancer. Int J Clin Oncol 2014; 19:842-51. [PMID: 24292333 DOI: 10.1007/s10147-013-0639-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 11/01/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND Mouse double minute 2 (Mdm2) is a negative regulator of the tumor suppressor p53. The p53-Mdm2 pathway may play a role in cancer development and prognosis, although the role of p53-Mdm2 in breast cancer remains unclear. METHODS p53 and Mdm2 expressions were determined by immunohistochemistry of tissue microarrays of 865 breast cancer patients who underwent surgery. Clinicopathological characteristics and survival data were analyzed. Mdm2 expression was categorized into four groups: negative, cytoplasm positive, nucleus positive, and concurrent nuclear and cytoplasm positive (N+&C+). RESULTS Negative, cytoplasm-positive, nucleus-positive, and N+&C+ expressions of Mdm2 were observed in 59.2, 10.9, 27.8, and 2.1 % of patients, respectively. The N+&C+ group was associated with larger tumor size, higher grade, negativity for estrogen and progesterone receptors, HER2 positivity, high Ki-67 index, p53 positivity, and triple negative breast cancer. p53-positive tumors showed poorer overall survival than p53-negative tumors. The nucleus-positive and N+&C+ groups showed poorer disease-free survival than the negative and cytoplasm-positive groups. In multivariate analysis, nuclear Mdm2 expression including the N+&C+ group was significantly related to poor prognosis. CONCLUSIONS Concurrent nuclear and cytoplasmic Mdm2 expression was an independent prognostic factor in patients with breast cancer. Subcellular localization of Mdm2 expression should be considered in the evaluation of Mdm2 in breast cancer.
Collapse
|
7
|
Abstract
Overexpression of the oncoprotein MDM2, an important regulator of the p53 tumor suppressor protein, is often observed in breast cancer tissues and cell lines, particularly in those which express estrogen receptor alpha (ERalpha). In MCF-7 breast cancer cell line possessing wild-type p53, ERalpha, and overexpressing MDM2, p53 accumulation was stimulated by 17beta-estradiol (E2) in a concentration-dependent manner. On the other hand, E2 caused no change of the expression of p53 mRNA, indicating that E2 affects p53 at the post-transcriptional level. To analyze the mechanism of p53 accumulation by E2, the stability of p53, ERalpha and MDM2 proteins was analyzed in the presence of cycloheximide under an E2-supplemented or -depleted condition. E2 significantly extended the half-life of p53 protein, but shortened that of ERalpha in MCF-7 cells. E2 significantly decreased the stability of p90(MDM2) and p60(MDM2) in MCF-7. Interestingly, E2 increased the ratio p60(MDM2)/p90(MDM2) inversely proportionally to the degradation of p53. These results suggest that the ratio of the two MDM2 proteins, p90(MDM2) and p60(MDM2), may affect the accumulation of wild-type p53 protein in response to E2.
Collapse
Affiliation(s)
- Naoki Okumura
- Second Department of Surgery, Gifu University School of Medicine, Gifu 500-8705, Japan.
| | | | | | | | | | | |
Collapse
|
8
|
Abstract
The overexpression of the oncogene product MDM2 is often observed in human breast cancer cells, especially in estrogen receptor (ER)-positive ones. To study the role of MDM2 protein in ER-positive breast cancer, we have established cell lines derived from MCF-7 which stably express increased and decreased levels of MDM2 by transfection of a mammalian expression vector containing human mdm2 cDNA in sense and antisense orientations, respectively. Interestingly, MDM2 overexpression in MCF-7 cells afforded a remarkable growth advantage under estradiol (E2)-supplemented condition. Then, we analyzed the expression of p53, which is an important regulator of growth and the cell cycle. Unexpectedly, the p53 accumulation induced by E2 was remarkably higher in MCF-7 cells stably overexpressing MDM2 than in the parent MCF-7 cells. On the other hand, reduction of MDM2 suppressed the E2-induced increase in p53 protein. Moreover, mdm2 antisense oligonucleotides prevented E2-induced accumulation of p53. In the steady state, the cellular levels of p53 were also correlated with those of MDM2. These interactions are not consistent with the well-known role of MDM2, which acts as a negative regulator for p53 by inhibiting its function and promoting its rapid degradation. These results suggest that MDM2 may regulate the expression of p53 in the steady state and in response to E2 in breast cancer cells, and imply a novel and important role of MDM2 during breast carcinogenesis.
Collapse
Affiliation(s)
- S Saji
- 2nd Department of Surgery, Gifu University School of Medicine.
| | | | | | | | | | | |
Collapse
|
9
|
Abstract
Several oncoproteins or tumor suppressor gene products have been indicated to be of value as predictors of the de novo resistance to cytotoxic agents. In this study, we have investigated the role of MDM2 (murine double minutes) overexpression in doxorubicin resistance of breast cancer. Immunocytochemical analysis demonstrated that MDM2-positive tumors, even with p53-negative phenotype, were significantly more resistant to doxorubicin treatment compared to MDM2-negative tumors. An in vitro experimental model using stable mdm2-transfected MCF-7 cells carrying wild-type p53 confirmed that the cells become approximately 3-fold more resistant to doxorubicin as a result of MDM2 overexpression, and the wild-type p53 function, such as the induction of p21Waf1 following DNA damage, was significantly suppressed. MDM2 overexpression is suggested to be a novel marker for predicting lack of response to doxorubicin treatment in breast cancer patients.
Collapse
Affiliation(s)
- A Suzuki
- Department of Surgery, Tokyo Metropolitan Komagome Hospital
| | | | | | | | | | | |
Collapse
|