%0 Journal Article
%T Positive Correlation between PMS2 Deficiency and PD-L1 Expression in Pancreatic Cancer
%A Cailing Jiang
%A Chunyan Dang
%A Ruilong He
%A Limin Cheng
%A Yiying Bai
%A Xinyu Bai
%A Xin Wang
%A Qianhui Chen
%A Hongbin Yang
%A Zhengxin Zhang
%A Xiaotong Zhang
%A Yan Chen
%A Qian Xu
%A Lei Liu
%A Li Zhang
%J Advances in Bioscience and Biotechnology
%P 74-90
%@ 2156-8502
%D 2023
%I Scientific Research Publishing
%R 10.4236/abb.2023.142005
%X <b><span style=\"font-family:&quot;\">Background:</span></b><span style=\"font-family:&quot;\"> Pancreatic
cancer is one of the most lethal types of cancer, and immunotherapy has become a
promising remedy with advancements in tumor immunology. However, predicting the
clinical response to immunotherapy in pancreatic cancer remains a dilemma for clinicians.<b> Methods:</b> GEPIA database was used to analyze
the differential expression of MMR and PD-L1 genes in 33 common cancer types including
pancreatic cancer. The expression levels of MMR and PD-L1 genes were downloaded
from the GEPIA and GEO databases to analyze the correlation between MMR genes and
PD-L1, and the clinicopathological and survival information were downloaded from
the TCGA databases to analyze the relationship between the expression of MMR, PD-L1
and&nbsp;clinicopathological characteristics, prognosis.
Meanwhile, the tumor tissue samples of 41 patients with pancreatic cancer were collected,
and the protein expression levels of MMR and PD-L1 were
detected by immunohistochemical assay. Furthermore, we analyzed the correlation
between MMR and PD-L1, and the correlation between the expression of MMR, PD-L1
and clinicopathological characteristics, prognosis of pancreatic cancer patients. <b>Results:</b> Bioinformatics analysis showed that MLH1, MLH3, MSH2, MSH3, and
PMS2 were highly expressed in most cancer types including pancreatic cancer (<i>P</i> &lt; 0.05). TCGA data revealed that MLH1 expression was related to gender (<i>P</i> = 0.012), clinical stage (I vs II: <i>P</i> = 0.016), MSH2
expression was related to clinical stage (<i>P</i> &lt; 0.05), T stage (T3 vs
T4: <i>P</i> = 0.039), and MSH3 expression was related to T stage (<i>P</i> &lt;
0.05). Besides, both MSH2 expression (<i>P</i> &lt; 0.001) and MSH6 (<i>P</i> =
0.044) were significantly associated with prognosis. GEPIA data also showed that
MSH2 expression was related to prognosis (<i>P</i> = 0.008). The correlation analysis
revealed that the expressions MSH2, MLH1, PMS2 had strong correlations with PD-L1
both in GEPIA and GEO databases. Real-world data indicated that of the 41 pancreatic
cancer patients, 5 cases had MLH1 deletion, 5 cases had MSH2 deletion, 4 cases had
PMS2 deletion, and 12 cases had PD-L1 positive expression. Notably, PMS2 deletion
was associated with PD-L1 positive expression (<i>P</i> = 0.035). In addition, MLH1
was related to clinical stage (<i>P</i> = 0.033), age (<i>P</i> = 0.048), and MSH2
was related to clinical stage (<i>P</i> = 0.033). However, MLH1 (<i>P</i> = 0.697),
MSH2 (<i>P</i> = 0.956), PMS2
%K Pancreatic Cancer
%K PD-L1
%K PMS2
%K Mismatch Repair Protein
%K Correlation
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=123230