- Title
- Identification of the NR2C subtype of the N-Methyl-D-Aspartate Receptor (NMDAR) as a potential molecular target for melanoma treatment
- Creator
- Tabatabaee, Hessam
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2021
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- Cutaneous melanoma is a type of skin cancer that arises from uncontrolled proliferation of epidermal melanocytes. Melanocytes are dendritic cells located in the epidermis layer of the skin. They originate from the embryonic neural crest population of cells that during development migrate to the skin, hair follicles, eyes and to a lesser extent, occupy other sites of the body such as meninges, adipose tissues and the anogenital tract. One of the most important advances in the history of the melanoma field was the discovery of c-KIT and BRAF as relatively successful therapeutic targets in patients with melanoma. However, since c-KIT or BRAF mutations are not found in all melanoma patients, and even patients who harbour these mutations are partially responsive to the drugs may develop resistance to the inhibitors, it is an imperative to search for additional melanoma drug targets. Since melanocytes originate from the neural crest region during embryonic development, their ability to retain certain neuronal features may introduce exciting novel insights associated with melanoma formation and progression. In particular, ion channels on the surface membrane provide distinct therapeutic targets due to their high accessibility from the extracellular milieu. Through analysis of publicly available melanoma datasets here we identified GluN2C ion channels as a highly upregulated subtype of NMDARs in metastatic melanoma. Upregulation of GluN2C was confirmed in a panel of melanoma cell lines and fresh melanoma isolates. Strikingly, silencing of GluN2C markedly reduced viability and clonogenicity in melanoma cells. Consistently, a pharmacological inhibitor of GluN2C potently killed melanoma cells with minimal effects on melanocytes. Killing of melanoma cells by inhibition of GluN2C was not due to induction of apoptosis, since a general caspase inhibitor Z-VAD-FMK failed to rescue cells from dying. In contrast, antioxidants Ferrostatin-1 and Liproxstatin-1 blocked the induced cell death by GluN2C inhibition suggesting that the killing of melanoma cells is majorly due to a lipid peroxide-mediated type of necrotic cell death known as Ferroptosis. Moreover, our in depth computational analysis of RNA-seq results along with the experimental data provided a mechanistic insight of the integrated stress response (ISR) and p-eIF2⍺⎼ATF4⎼CHOP activation as the downstream pathway leading to ferroptotic phenotype following GluN2C inhibition in melanoma. Lastly, our results obtained from the three-dimensional spheroid culture showed that similar to monolayer culture, UBP141 potently killed melanoma cells by disrupting their ability to aggregate and form spheroids in hanging drop culture, demonstrating a proof of concept that withholds a promising approach in the treatment of melanoma. Collectively, these results uncover a potential role for GluN2C ion channels in the pathogenesis of melanoma and suggest that these ion channels may constitute a promising target for melanoma treatment.
- Subject
- melanoma; ion channels; NMDA receptors; melanoma treatment
- Identifier
- http://hdl.handle.net/1959.13/1421337
- Identifier
- uon:37717
- Rights
- Copyright 2021 Hessam Tabatabaee
- Language
- eng
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| Thumbnail | File | Description | Size | Format | |||
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| View Details Download | ATTACHMENT01 | Thesis | 3 MB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | ATTACHMENT02 | Abstract | 548 KB | Adobe Acrobat PDF | View Details Download |