Identification of CCNB2 as A Potential Non-Invasive Breast Cancer Biomarker in Peripheral Blood Mononuclear Cells Using The Systems Biology Approach

OBJECTIVE

Breast cancer (BC) still remains an imperative clinical issue, despite advances in the diagnosis, prognosis and treatment modalities of this malignancy. Hence, progress has been made to identify non-invasive, high sensitive and specific biomarkers. Since immune system affects development of breast cancer, peripheral blood mononuclear cells (PBMCs) -a subpopulation of immune cells- can be considered as a promising tool in the field of BC biomarker research. In the current study, we initially attempted to use concept of the present shared biomarkers in solid tumors and systemic immune profile and then evaluate correlation of these biomarkers to clinical use in cancer research.

MATERIALS AND METHODS

In this experimental study, available microarray gene expression datasets of BC as well as the related PBMCs were retrieved and downloaded from the Gene Expression Omnibus (GEO) database, followed by analysis using GEO2R along with affylmGUI, a R-based package, to obtain differentially expressed genes (DEGs). Signature genes from 20 types of cancer were also applied to validate DEGs. Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was carried out to assess mRNA level of CCNB2 in PBMC of the BC patients and healthy subjects.

RESULTS

DEGs analysis for the transcription profile of BC cells and PBMCs showed two shared targets, CCNB2 and PGK1. Validation with systems biology using reweighted 20 types of cancer signature genes revealed that CCNB2 is the only common target in BC and its related PBMCs, which was further validated by qRT-PCR implying a significant increase in the level of CCNB2 in the BC patients.

CONCLUSION

Results of this study demonstrated that PBMCs are affected by BC cells and CCNB2 may be of value as a diagnostic biomarker for breast cancer. However, verification would require future detailed experimental plans.

Crosstalk between Tumor Cells and Immune System Leads to Epithelial-Mesenchymal Transition Induction and Breast Cancer Progression

Herein, we review the current findings of how a variety of accessory cells could participate in shaping the tumor microenvironment and supporting the mechanisms by which cancer cells undertake the epithelial-mesenchymal transition (EMT). EMT, a complex of phenotypic changes, promotes cancer cell invasion and creates resistance to chemotherapies. Among the accessory cells present in the EMT, immune cells (both native and adaptive) can reciprocally influence the tumor cells features, promote EMT and negatively regulate the anticancer immune response. In this review, we look over the role of EMT in crosstalk between tumor cells and the immune system, with specific emphasis on breast tumors. Finally, we suggest that understanding the role of immune cells in cancer progression could create new opportunities for diagnostic and therapeutic interventions in cancer combination therapy.

Identification and Validation of Stage-Associated PBMC Biomarkers in Breast Cancer Using MS-Based Proteomics

Background: It is well-described that the transcriptome of peripheral blood mononuclear cells (PBMCs) can be altered in the context of many malignancies to allow them avoid the effective immune response, which leads to cancer invasiveness. Here, we used an MS-based strategy to discover biomarkers in the PBMCs of breast cancer (BC) patients and validated them at different stages of BC. Methods: PBMCs were isolated from the breast cancer patients and were cultured alone or co-cultured with breast cancer cell lines. The role of PBMC in the invasion property of breast cancer cells was explored. NF-kB activity was also measured in the co-cultured breast cancer cells. Identification of protein profiles in the secretome and proteome of the co-cultured PBMCs was performed using SWATH mass spectrometry. Pathway enrichment and gene ontology analyses were carried out to look for the molecular pathways correlated with the protein expression profile of PBMCs in the breast cancer patients. Quantitative real-time polymerase chain reaction (qPCR) was performed to validate the candidate genes in the PBMC fraction of the breast cancer patients at the primary and metastatic stages. In silico survival analysis was performed to assess the potential clinical biomarkers in these PBMC subtypes. Results: PBMCs could significantly increase the invasion property of the BC cells concomitant with a decrease in E-cadherin and an increase in both Vimentin and N-cadherin expression. The NF-kB activity in the BC cells significantly increased following co-culturing implying the role of PBMCs in EMT induction. Enrichment analysis showed that the differentially expressed proteins in PBMCs are mainly associated with IL-17, PI3K-Akt, and HIF-1 signaling pathway, in which a set of seven proteins including TMSB4X, HSPA4, S100A9, SRSF6, THBS1, CUL4A, and CANX were frequently expressed. Finally, in silico analysis confirmed that a gene set consisting of S100A9, SRSF6, THBS1, CUL4A, and CANX were found to provide an insight for the identification of metastasis in breast cancer patients. Conclusion: In conclusion, our study revealed that the protein expression profile in PBMCs is a reflection of the proteins expressed in the BC tissue itself; however, the abundance level is different due to the stage of cancer.

Two Novel Tri-Aryl Derivatives Attenuate the Invasion-Promoting Effects of Stromal Mesenchymal Stem Cells on Breast Cancer

Background:

The concept of Epithelial-Mesenchymal Transition (EMT) to promote carcinoma progression has been recognized as a venue for research on novel anticancer drugs. Triaryl template-based structures are one of the pivotal structural features found in a number of compounds with a wide variety of biological properties including anti-breast cancer. Among the various factors triggering EMT program, cyclooxygenase-2 (COX-2), NF-κB as well as the transforming growth factor-beta (TGF-β) have been widely investigated.

Objective:

Here, we aim to investigate the effect of two novel compounds A and B possessing triaryl structures, which interact with both COX-2 and TGF-β active sites and suppress NF-κB activation, on EMT in a co-culture system with breast cancer and stromal cells.

Methods:

MDA-MB-231 and bone-marrow mesenchymal stem (BM-MS) cells were co-cultured in a trans-well plate. Migration, matrigel-based invasion and colony formation in soft agar assays along with Real- time PCR and Western blot analysis were performed to examine the effect of compounds A and B on the invasive properties of MDA-MB-231 cells after 72 hours of co-culturing with BM-MSCs. In addition, TGF-beta interaction was investigated by Localized Surface Plasmon Resonance (LSPR).

Results:

BM-MSCs enhanced migration, invasion and anchorage-independent growth of the co-cultured MDAMB- 231 cells. A reduction in E-cadherin level concomitant with an increase in vimentin and N-cadherin levels following the co-culture implied EMT as the underlying process. Compounds A and B inhibited invasion and anchorage-independent growth of breast cancer cells co-cultured with BM-MSCs at 10µM. The observed inhibitory effects along with an increase in E-cadherin and a reduction in vimentin and ZEB2 levels suggest that the anti-invasive properties of compounds A and B might proceed through the blockade of stromal cell-induced EMT, mediated by their interaction with TGF-beta.

Conclusion:

These findings introduce compounds A and B as novel promising agents, which prevent EMT in invasive breast cancer cells.