Hi there,
I used L-NAME to treat cancer cells. Then I did LDH and MTT, according to these results, MTT showed the cell viability was above 100% compared with control, and LDH showed cytotoxicity was nearly unchaged.
However, I saw some studies suggested that L-NAME could inhibit cancer cells proliferation. I'm confused with it.
Does anyone have some experiences with it?
Many thanks.
Hello Tingting Wang
L-NAME helps to prevent tumor angiogenesis.
Angiogenesis is associated with tumor growth and metastasis. The NO pathway appears to play a key role in tumor angiogenesis . L-NAME is the NOS inhibitor. L-NAME can cause NO deprivation which can cause tumor feeder vessels to constrict, reducing tumor blood flow. The delivery of oxygen and essential nutrients to the developing tumor is impaired as a consequence, hampering further growth.
For the cytotoxicity assay (MTT), try increasing the concentration of L-NAME. Increased concentration of L-NAME might show the cytotoxicity effect.
When you are working with L-NAME, you may consider performing not just the cytotoxicity assay (MTT) but also migration assay as suppression of endogenous NOS could impair EMT and cell migration. You may also consider estimating the levels of nitric oxide production using the nitrate/nitrite assay by treating the cells with L-NAME for 24 hours and then collecting the cell culture supernatant at various time points for the assay.
Also, consider performing some animal experiments as NOS inhibition could reduce tumor growth and tumor-initiating capacity and prevent metastases.
Good Luck!
Thank you Malcolm Nobre
There are some papers suggesting L-NAME is a non-selective NOS inhibitor, which could decrease cancer progression. But a study (10.1038/s41586-019-1100-z) suggested that combing HFD and L-NAME could upregulate iNOS expression in the heart.
So maybe L-NAME also promotes cancer growth?
This is just my assumption. Because I'm confused with L-NAME. Why dose iNOS increase in the context of L-NAME although it's a pan-NOS inhibitor? maybe different iNOS expression in different tissues? heart vs. tumor?
Dear Tingting Wang ,
When doing MTT, be careful not to have too many cells. When it is excessive, cell viability can be seen more than control.
good luck
- Badges
- Science method