Hey remember how I told you all scientists are using herpes, the regular-ol much hated cold-sore virus, to treat/cure cancers?
The approach has left us with miraculous effects… or no effects at all.
I mean, half of the melanoma patients lived A LOT LONGER than they were supposed to, several of them ending up with no evidence of disease… But that also means that half werent helped at all.
HSV-1 couldnt help a child with rhabdomyosarcoma… when it was ‘supposed’ to work so well.
Of course that question has a collection of complex answers, and there are lots of scientists working on that question from many angles– But a group of folks might have figured out one problem: Chemo.
Something was going ‘wrong’ with the system. Tumors are messed up. One of the features of some of them is a protein called NF-κB is over-expressed. This helps the tumor grow grow grow go go go. Chemotherapy upregulates NF-κB too, because healthy cells do this normally when exposed to a stressor like chemotherapy. And as luck would have it, HSV-1 LOVEEEEEES NF-κB for replication, which leads to cell death, the oncolytic (cancer-killing) features of HSV. This system was designed with all of this in mind- It should be PERFECT.
Except that wasnt happening.
The over-expression of NF-κB was pissing off HSV-1, leading to less virus, and less tumor killing.
Because ‘cancer’ is not a monolithic entity, and ‘chemotherapy’ is not a monolithic treatment, sometimes everything worked in concert, like it was supposed to (lots of NF-κB = lots of HSV-1 = lots of tumor killing).
Only some of the chemo medications used interfered with the activity of HSV.
So every time scientists try one of these HSV vs Cancer trials, they need to figure out if the drugs their patients are on are ones that either help HSV work better, or at least, dont interfere with HSV. That might help us get HSV to work against cancers it has failed against/not 100% in trials.
Ugh. Cancer is a mess.