Highlights
- •The expression of chromobox (CBX) family members was varied in breast cancer and several members of CBX family were associated with molecular subclasses, tumor stages, lymph node status and TP53 mutational status.
- •Higher expression of CBX2/3 was associated with worse overall survival, postprogression survival, relapse-free survival, and distant metastasis-free survival, which indicated a poor prognosis while higher levels of CBX 6/7 may represent a better prognosis.
- •CBX family may serve as an important regulator in breast cancer and its functional role is worthy of further study.
Abstract
Background: Chromobox proteins are canonical components of the Polycomb group family and play
pivotal roles in several cancers. However, little is known about the function, prognostic
value and drug sensitivity of CBX family members in breast cancer.Methods: In this study we investigated the expression, prognosis value and drug sensitivity
of CBX family in breast cancer using the ONCOMINE, GEPIA, Human Protein Atlas and
Kaplan-Meier Plotter databases, etc. and preliminary verified the expression of CBX
family in breast cancer cell lines by RT-qPCR.Results: We found that the expression levels of CBX1/2/3/4/8 members were elevated in breast
cancer tissues compared to adjacent normal breast tissues, while the expression levels
of CBX6/7 genes were reduced in breast cancer tissue. In vitro qRT-PCR validated the
expression differences of CBX1/2/3/4/8 in breast cancer cell lines. Further analysis
showed expression of CBX family members was remarkably correlated with cancer subgroups.
As nodal metastasis status increased, the mRNA expression of CBX1/2/3/4/8 members
tended to be higher, while CBX6/7 tended to be lower. The expression of CBX1/2/3 was
higher in patients with TP53 mutation and CBX6/7 expression tended to be lower in
patients with TP53 mutation groups. High transcription levels of CBX2/3 were significantly
associated with shorter overall survival in breast cancer patients, while lower expression
of CBX4/5/6/7 members was associated with unfavorable overall survival. Moreover,
a high mutation rate of CBX gene members (43%) was observed in breast cancer patients,
and genetic alterations in CBX genes was associated with poor prognosis.Conclusion: Taken together, our results indicated that CBX2/3/6/7/8 could be considered prognostic
and therapeutic biomarkers of breast cancer and are worthy of further study.
Keywords
Abbreviations:
CBX (Chromobox), ER (estrogen receptor), PR (progesterone receptor), Her2 (human epidermal receptor 2), TNBC (triple-negative breast cancer), FC (fold-change), TCGA (The Cancer Genome Atlas), GO (Gene Ontology), KEGG (Kyoto Encyclopedia of Genes and Genomes), PPI (protein-protein interaction), OS (overall survival relapse-free survival), PPS (postprogression survival), RFS (relapse-free survival), DMFS (distant metastasis-free survival)To read this article in full you will need to make a payment
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Article info
Publication history
Published online: February 15, 2023
Accepted:
February 9,
2023
Received in revised form:
February 4,
2023
Received:
September 10,
2022
Publication stage
In Press Journal Pre-ProofIdentification
Copyright
© 2023 Elsevier Inc. All rights reserved.
