Getting sticky with it: Phospholipid found to play a key role in epithelial cell adhesion

Now, while the role of proteins in maintaining cellular identity is well-researched, we can't help but wonder-do lipids (fatty molecules) also play a role in characterizing cells and preventing EMT?

Under the guidance of Dr. Yoshikazu Nakamura and Dr. Kaori Kanemaru, researchers from Tokyo University of Science (TUS), Tokyo University of Pharmacy and Life Sciences, Tokyo Medical and Dental University, Akita University, Hokkaido University, and Kobe University have tried to find an answer to this question.

"We know lipids are an important class of biomolecules, necessary for certain cellular functions. One such lipid, a phosphatidylinositol, forms a phospholipid called phosphatidylinositol bisphosphate (PIP₂)," Associate Professor Dr. Nakamura from TUS dives into the topic. He tells us that PIP₂ is important because it is crucial for the formation of signaling molecules that regulate cell proliferation, survival, and migration. "We had evidence that higher amounts of PIP₂ were found in the epidermal layer of skin, so we hypothesized that this phospholipid contributed to the properties and characterization of epithelial cells."

The findings from their study have been published in Nature Communications. The paper describes how the team used a battery of analytical techniques including chromatography, mass spectroscopy, immunofluorescence, retroviral expression, and real-time quantitative PCR to confirm that PIP₂ plays a critical role in the determination of epithelial identity.

"We saw that epithelial cells lost their properties when PIP₂ was depleted from their cell membranes. On the other hand, osteosarcoma cells (which are cancerous, non-epithelial cells) gained epithelial cell-like properties when PIP₂ was produced in their plasma membranes." says Dr. Nakamura, with a look of excitement. The group was also able to show that PIP₂ regulates these epithelial properties by recruiting Par3 -- a protein which guides vesicles intracellularly -- to the plasma membrane. Once in the plasma membrane, Par3 facilitates the formation of adherens junctions (one of the cellular junctions discussed above) which anchor neighboring cells together. This partially prevents EMT, and hence, progression of cancer.

"So," Dr. Nakamura explains, "In theory, PIP₂'s partial inhibition of EMT could halt cancer progression, making this phospholipid an attractive target molecule for anti-cancer treatment."

TUS' research has opened a new avenue for the development of anti-cancer drug development, possibly giving us a solution that will "stick."