Abstract A039: The role of long noncoding RNAs in epithelial to mesenchymal transition and cancer stem cells

Cancer stem cells (CSCs) possess properties such as self-renewal, resistance to apoptotic cues, quiescence, and DNA-damage repair capacity. Moreover, CSCs strongly influence the tumour microenvironment (TME) and may account for cancer progression, recurrence, and relapse. CSCs represent a distinct subpopulation in tumours and the detection, characterisation, and understanding of the regulatory landscape and cellular processes that govern their maintenance may pave the way to improving prognosis, selective targeted therapy, and therapy outcomes. In this review, we have discussed the characteristics of CSCs identified in various cancer types and the role of autophagy and long noncoding RNAs (lncRNAs) in maintaining the homeostasis of CSCs. Further, we have discussed methods to detect CSCs and strategies for treatment and relapse, taking into account the requirement to inhibit CSC growth and survival within the complex backdrop of cellular processes, microenvironmental interactions, and regulatory networks associated with cancer. Finally, we critique the computationally reinforced triangle of factors inclusive of CSC properties, the process of autophagy, and lncRNA and their associated networks with respect to hypoxia, epithelial-to-mesenchymal transition (EMT), and signalling pathways.

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Oncogenic Role of Exosomal Circular and Long Noncoding RNAs in Gastrointestinal Cancers

International Journal of Molecular Sciences ◽

10.3390/ijms23020930 ◽

2022 ◽

Vol 23 (2) ◽

pp. 930

Author(s):

Ba Da Yun ◽

Ye Ji Choi ◽

Seung Wan Son ◽

Gabriel Adelman Cipolla ◽

Fernanda Costa Brandão Berti ◽

...

Keyword(s):

Epithelial To Mesenchymal Transition ◽

Cell Communication ◽

Noncoding Rnas ◽

Long Noncoding Rnas ◽

Circular Rnas ◽

Gastrointestinal Cancers ◽

Gastrointestinal Malignancies ◽

Mesenchymal Transition ◽

Novel Therapeutic Strategies

Circular RNAs (circRNAs) and long noncoding RNAs (lncRNAs) are differentially expressed in gastrointestinal cancers. These noncoding RNAs (ncRNAs) regulate a variety of cellular activities by physically interacting with microRNAs and proteins and altering their activity. It has also been suggested that exosomes encapsulate circRNAs and lncRNAs in cancer cells. Exosomes are then discharged into the extracellular environment, where they are taken up by other cells. As a result, exosomal ncRNA cargo is critical for cell–cell communication within the cancer microenvironment. Exosomal ncRNAs can regulate a range of events, such as angiogenesis, metastasis, immune evasion, drug resistance, and epithelial-to-mesenchymal transition. To set the groundwork for developing novel therapeutic strategies against gastrointestinal malignancies, a thorough understanding of circRNAs and lncRNAs is required. In this review, we discuss the function and intrinsic features of oncogenic circRNAs and lncRNAs that are enriched within exosomes.

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Pivotal Role of AKT2 during Dynamic Phenotypic Change of Breast Cancer Stem Cells

Cancers ◽

10.3390/cancers11081058 ◽

2019 ◽

Vol 11 (8) ◽

pp. 1058 ◽

Cited By ~ 10

Author(s):

Gener ◽

Rafael ◽

Seras-Franzoso ◽

Perez ◽

Pindado ◽

...

Keyword(s):

Breast Cancer ◽

Stem Cells ◽

Cancer Stem Cells ◽

Epithelial To Mesenchymal Transition ◽

Distant Metastases ◽

Metastatic Potential ◽

Phenotypic Change ◽

Primary Tumors ◽

Mesenchymal Transition

Therapeutic resistance seen in aggressive forms of breast cancer remains challenging for current treatments. More than half of the patients suffer from a disease relapse, most of them with distant metastases. Cancer maintenance, resistance to therapy, and metastatic disease seem to be sustained by the presence of cancer stem cells (CSC) within a tumor. The difficulty in targeting this subpopulation derives from their dynamic interconversion process, where CSC can differentiate to non-CSC, which in turn de-differentiate into cells with CSC properties. Using fluorescent CSC models driven by the expression of ALDH1A 1(aldehyde dehydrogenase 1A1), we confirmed this dynamic phenotypic change in MDA-MB-231 breast cancer cells and to identify Serine/Threonine Kinase 2 (AKT2) as an important player in the process. To confirm the central role of AKT2, we silenced AKT2 expression via small interfering RNA and using a chemical inhibitor (CCT128930), in both CSC and non-CSC from different cancer cell lines. Our results revealed that AKT2 inhibition effectively prevents non-CSC reversion through mesenchymal to epithelial transition, reducing invasion and colony formation ability of both, non-CSC and CSC. Further, AKT2 inhibition reduced CSC survival in low attachment conditions. Interestingly, in orthotopic tumor mouse models, high expression levels of AKT2 were detected in circulating tumor cells (CTC). These findings suggest AKT2 as a promising target for future anti-cancer therapies at three important levels: (i) Epithelial-to-mesenchymal transition (EMT) reversion and maintenance of CSC subpopulation in primary tumors, (ii) reduction of CTC and the likelihood of metastatic spread, and (iii) prevention of tumor recurrence through inhibition of CSC tumorigenic and metastatic potential.

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