Identification of Dipeptidyl Peptidase (DPP) Family Genes in Clinical Breast Cancer Patients via an Integrated Bioinformatics Approach

Abstract

Breast cancer is a heterogeneous disease involving complex interactions of biological processes; thus, it is important to develop therapeutic biomarkers for treatment. Members of the dipeptidyl peptidase (DPP) family are metalloproteases that specifically cleave dipeptides. This family comprises seven members, including DPP3, DPP4, DPP6, DPP7, DPP8, DPP9, and DPP10; however, information on the involvement of DPPs in breast cancer is lacking in the literature. As such, we aimed to study their roles in this cancerous disease using publicly available databases such as cBioportal, Oncomine, and Kaplan–Meier Plotter. These databases comprise comprehensive high-throughput transcriptomic profiles of breast cancer across multiple datasets. Furthermore, together with investigating the messenger RNA expression levels of these genes, we also aimed to correlate these expression levels with breast cancer patient survival. The results showed that DPP3 and DPP9 had significantly high expression profiles in breast cancer tissues relative to normal breast tissues. High expression levels of DPP3 and DPP4 were associated with poor survival of breast cancer patients, whereas high expression levels of DPP6, DPP7, DPP8, and DPP9 were associated with good prognoses. Additionally, positive correlations were also revealed of DPP family genes with the cell cycle, transforming growth factor (TGF)-beta, kappa-type opioid receptor, and immune response signaling, such as interleukin (IL)-4, IL6, IL-17, tumor necrosis factor (TNF), and interferon (IFN)-alpha/beta. Collectively, DPP family members, especially DPP3, may serve as essential prognostic biomarkers in breast cancer.

Potential Prognostic Biomarkers of OSBPL Family Genes in Patients with Pancreatic Ductal Adenocarcinoma

“…The Kaplan–Meier plotter contains information about the associations of gene expressions with the survival of patients with many kinds of cancers ( , accessed on 15 April 2021) [ 26 ]. We analyzed the prognostic merits of the target genes [ 27 ] with the KM plotter using median values, hazard ratios (HRs) >1, and a log rank of <0.05 [ 28 , 29 , 30 , 31 , 32 , 33 ].…”

Expression Profiles and Prognostic Value of FABPs in Colorectal Adenocarcinomas

“…To study the list of classes of genes or proteins in terms of biological functions which may have a relationship with a disease phenotype, this research used an integrative analysis involving several databases such as STRING, cBioPortal, and MetaCore [47][48][49][50][51][52]. The STRING database (https://www.string-db.org/ accessed on 14 May 2021), consisting of 24,584,628 proteins from 5090 organisms, was used to reveal protein-protein interactions (PPIs) [53,54].…”

Multidimensional Analysis of the Role of Charged Multivesicular Body Protein 7 in Pan-Cancer

“…The Human Protein Atlas provides immunohistochemical evidence of differential expression of CHMP7 in normal and tumor tissues at the pathological level. [28][29][30] R software (version 3.6.3) was employed to further explore the correlation between CHMP7 expression levels and clinicopathological features.…”