Are increased levels of UCHL1 a compensatory response to disrupted ubiquitin homeostasis in spinal muscular atrophy and do not represent a viable therapeutic target?
Pharmacological inhibition of UCHL1 exacerbates rather than ameliorates disease symptoms in a mouse model of SMA. Thus, pharmacological inhibition of UCHL1 is not a viable therapeutic target for SMA. Moreover, increased levels of UCHL1 in SMA likely represent a downstream consequence of decreased Uba1 levels, indicative of an attempted supportive compensatory response to defects in ubiquitin homeostasis caused by low levels of SMN protein.
Awareness of this possible long-term complication during PLD treatment should enhance the likelihood of early detection of oral lesions in these patients. Decisions to continue maintenance PLD after complete response of the original cancer should perhaps consider the benefits of delaying ovarian cancer recurrence versus the possible risk for a secondary cancer.