A rare type of lung cancer known as Malignant Pleural Mesothelioma (MPM) may have received a breakthrough in the advancement of its treatment thanks to near-infrared radiation (NIR) therapy. That’s according to an insightful article we read on Technology Networks (1).
You may not have specifically heard of MPM. It’s a type of lung cancer which affects the organ’s lining, typically developing several decades after exposure to asbestos. Over 2,600 people are diagnosed annually in the UK, often aged between 60-80 and it’s more commonly found in men.
Whilst at present there is unfortunately no cure, the article (1) outlines how a recent investigation into the effectiveness of a treatment known as near-infrared photoimmunotherapy (NIR-PIT) – which combines NIR and a cancer-targeting compound – has prompted the US Food & Drug Administration to fast-track the treatment for approval.
This investigation was carried out by Nishinaga et al.(2) and it could well represent a significant step forwards in discovering a potential cure for MPM.
Technology Network’s article (1) provides quotes from one of the scientists working on the investigation; Nagoya University oncologist Kazuhide Sato. Sato’s comments express his confidence in NIR-PIT in greatly advancing MPM therapy, making for interesting reading.
He said:“The lungs and chest cavity contain a large amount of air and are thus very good at effectively transmitting near-infrared light. NIR-PIT is a safe phototherapy option that can target a region of interest.”
‘Targeting a region of interest’ as Sato mentions is made possible by the cancer-targeting compound discussed consisting of an antibody – which targets a specific structure on the cancer cells – and a photoabsorber named IR700. When near-infrared light is shone on the cancer-affected area, the compound is able to latch onto the cancer cell membranes causing them to acutely rupture thus killing the tumour.
The finer details of the investigation and an explanation of how NIR-PIT can specifically target MPM are fascinating. The investigation focused on the antibody referred to as NZ-1 as this antibody is known to target a specific part of a transmembrane glycoprotein (an integral membrane protein that spans the entirety of the cell membrane) called Podoplanin. Per the article, the significance of Podoplanin is that it is particularly abundant in MPM cancer cells.
Nishinagaet al.’s research discovered that the NZ-1 antibody conjugates well with the photoabsorber IR700. Thus, when specifically bounded to the Podoplanin-positive cells – including MPM cancer cells – and irritated with near-infrared light, the cells immediately rupture.
Sato continues to explain the safety of this process: “The antibody-IR700 conjugate is also non-toxic to the body in the absence of near-infrared light irradiation. We thus thought that NIR-PIT could be an effective strategy for controlling localized MPM.”
Tests on mice injected with MPM tumours have been positive, indicating that the treatment does achieve success in fighting this cancer. However, further research is necessary to discover ways which ensure healthy Podoplanin-positive cells are not impacted.
It will certainly be of great interest to us to keep a close eye on the future developments of this study in the hope that we’re not far off a safe, effective and reliable treatment for MPM.
- Nishinaga,et al. (2020). ‘Targeted Phototherapy for Malignant Pleural Mesothelioma: Near-Infrared Photoimmunotherapy Targeting Podoplanin.’ Cells. DOI: 3390/cells9041019.