I am computational guy and hence apologies if the question is silly.
Can the same miRNA show upregulation and downregulation in the same disease? (Not in the same experiment, though). For e.g. can there be a instance of miRNA
hsa-miR-21 being upregulated in a disease glioblastoma in 1 study and in another study there is an occurrence of
hsa-miR-21 being down-regulated in glioblastoma. Is this possible?
As an example, I found:
hsa-miR-345 -> overexpression in pancreatic cancer (PMID: 16966691) and,
hsa-miR-345 -> downregulation in pancreatic cancer (PMID: 17149698)
Any pointers would be appreciated.