Xist noncoding RNA could act as a tumor suppressor gene in patients with classical Hodgkin's disease

Xist is a long noncoding RNA involved in the X chromosome inactivation in females. It may act as an onco-suppressor gene in hematologic malignancies, and its activity is strongly dependent from SATB1 gene expression. However, its potential role in Hodgkin's disease (HD) onset and progression is unknown.

Three gene expression microarray datasets were analyzed for the expression of Xist and SATB1 in patients with classical HD, namely, GDS4222 (130 patients and 54,000 gene features), GSE39134 (29 patients and 54,000 features), and E-MEXP-507 (29 patients and 27,648 probes). The first two were oligonucleotide arrays (platform: Affymetrix gene chip HG-U133-Plus2), whereas the latter was a cDNA two-channel array (platform: OncoChip. v2). Summary and time-dependent receiver operating characteristic (ROC) analysis were applied to obtain a summary measure (summary area under the ROC curve [sAUC]) of association between gene expression and unfavorable patient outcome in each probe set.

Xist was overexpressed among females in each data set. A slight overexpression was associated with a good prognosis both in males (sAUC = 0.75, 95% confidence interval [CI]: 0.70-0.80) and at a lesser extent, in females (sAUC = 0.64, 95% CI: 0.59-0.69). However, this finding was limited to the analysis of the biggest database (GDS4222). No association was found between Xist and SATB1 expression.

A reactivation of Xist might act as an onco-suppressor gene in male patients with HD, which seems independent from SATB1 expression. The possibility that Xist could contribute to the better survival of female patients should also be investigated.