Objective:
Alterations in the expression of several long non-coding RNAs (lncRNAs) have been shown in chronic hepatitis B-associated hepatocellular carcinoma (CHB-HCC). Here, we aimed to investigate the association between the expression of inflammation-associated lncRNA X-inactive specific transcript (
XIST
) and the type of inflammatory cells within the tumor microenvironment.
Material and Methods:
Twenty-one consecutive cirrhotic patients with CHB-HCC were included.
XIST
expression levels were investigated on formalin-fixed paraffin-embedded (FFPE) tumoral and peritumoral tissue samples by real-time polymerase chain reaction (RT-PCR). Immunohistochemical staining for CD3, CD4, CD8, CD25, CD163, CTLA4, and PD-1 were performed. The findings were statistically analyzed.
Results:
Of the 21 cases, 11 (52.4%) had tumoral and 10 (47.6%) had peritumoral
XIST
expression. No significant association was found between the degree of inflammation and
XIST
expression. The number of intratumoral CD3, CD4, CD8 and CD20 positive cells was higher in
XIST
-expressing tumors, albeit without statistical significance. Tumoral and peritumoral
XIST
expression tended to be more common in patients with tumoral and peritumoral CD4high inflammation. The number of intratumoral CD25 positive cells was significantly higher in
XIST
-expressing tumors (p=0.01). Tumoral
XIST
expression was significantly more common in intratumoral CD25high cases (p=0.04). Peritumoral
XIST
expression was also more common among patients with CD25high peritumoral inflammation, albeit without statistical significance (p=0.19).
Conclusion:
lncRNA
XIST
is expressed in CHB-HCC and its expression is significantly associated with the inflammatory tumor microenvironment, particularly with the presence and number of CD25 (+) regulatory T cells. In vitro studies are needed to explore the detailed mechanism.