Metabolic Effects of the Cancer Metastasis Modulator MEMO1

Area of Science:

• Biochemistry
• Cancer Biology
• Metabolic Regulation

Background:

• Cancer cells exhibit altered energy metabolism, with dysregulation of the tricarboxylic acid (TCA) cycle being a hallmark.
• MEMO1, a cancer metastasis modulator, interacts with iron and influences cellular iron homeostasis.
• Previous studies linked MEMO1 to mitochondrial respiration and TCA cycle genes in cancer cells.

Purpose of the Study:

• To investigate the role of MEMO1 in regulating TCA cycle metabolites in breast cancer cells.
• To determine the influence of iron availability on MEMO1's regulation of the TCA cycle.

Main Methods:

• Assessed the essentiality of TCA cycle enzymes using shRNA knockdown.
• Quantified TCA metabolites via liquid chromatography-tandem mass spectrometry (LC-MS/MS) in cells with varying MEMO1 expression (high, knockdown, knockout).
• Evaluated metabolite levels under iron-depleted, basal, and iron-supplemented conditions.

Main Results:

• Knockdown of ACO2 and OGDH inhibited cell proliferation, confirming TCA cycle's essentiality.
• Alpha-ketoglutarate and citrate levels increased in MEMO1 knockout cells, irrespective of iron.
• Fumarate, malate, and glutamate levels rose in MEMO1 knockout cells specifically under low iron conditions.

Conclusions:

• MEMO1 plays a significant role in regulating the TCA cycle within cancer cells.
• This regulation by MEMO1 is demonstrably iron-dependent.
• Understanding MEMO1's role in TCA cycle and iron metabolism may offer new therapeutic strategies for cancer.