Abstract:
Cancer remains a major health issue globally, with increasing incidence and mortality rates. While immunotherapy has revolutionized cancer treatment, not all patients benefit, urging the identification of predictive biomarkers. This study utilized public datasets and tumor samples to examine the expression and promoter hypermethylation of
DLEC1
in normal and tumor tissues, to evaluate its potential as prognostic and immunotherapy marker.
In vitro
and
in vivo
experiments on breast cancer (BrCa) cell lines were conducted to explore the functions and mechanisms of
DLEC1
. The prognostic significance of
DLEC1
downregulation and its impact on immune cell infiltration and immunotherapy efficacy were analyzed using the GEO and TCGA databases.
DLEC1
was frequently downregulated and methylated across multiple cancers. In BrCa, expression of
DLEC1
inhibited tumor cell proliferation, induced apoptosis, and activated the interferon lambda1 signaling pathway, indicating its important role as a
bona fide
tumor suppressor and immunoregulator. High
DLEC1
expression correlated with better prognosis in several cancer types and with increased immune cell infiltration. Cancer patients with high
DLEC1
expression showed improved overall and progression-free survival under immune checkpoint inhibitor therapies, such as anti-CTLA4, anti-PD1 and anti-PDL1.
DLEC1
promoter hypermethylation is a promising biomarker for cancer prognosis and potential immunotherapy response prediction. Its expression and promoter hypermethylation status could thus help to guide clinical treatment strategies for cancer patients, particularly of breast cancer.