Major hallmarks of cancer include metastasis and evading the immune system. Despite cutting edge treatments developed in an era of extensive cancer research, immunotherapy has not been proven efficient enough in solid tumors, and metastasis still accounts for the majority of cancer deaths. The overall unsatisfactory response rates to immunotherapy are mainly due to the lack of biomarkers that can predict a patient’s response and the lack of a good understanding of the different immune cell infiltration trends observed in tumors. To address these gaps in breast and prostate cancer, RNA sequenced data for breast and prostate cancer samples were obtained from The Cancer Genome Atlas (TCGA) and analyzed to identify immune evasion mechanisms and understand immune cell infiltration. Breast and prostate cancer populations were each clustered into different immune evasion groups. Then biomarkers predictive of the identified clusters were identified and could be used as predictors of immune evasion and the corresponding immunotherapy options. In breast cancer, 77.4% of the clustered tumor specimens showed evasion through transforming growth factor-beta (TGF-β), 57.8% through decoy receptor 3 (DcR3), 48.0% through cytotoxic T-lymphocyte-associated protein 4 (CTLA4), and 34.3% through programmed cell death-1 (PD-1). Prostate cancer clustering showed immunologic ignorance in 89.77% of samples, upregulated CTLA4 in 58.8%, and upregulated DcR3 expression in 51.6%. However, in most clusters, there were different combinations of evasion mechanisms, which could explain the failure of immune monotherapy approaches. The immune profiling of breast cancer samples suggests that immunologically cold tumors are not only less immunogenic than hot tumors, but also have a high abundance of the pro-tumorigenic M2 macrophages and a stiff matrix, all of which can impede immune cell infiltration. Thus, M2 is a novel prognostic factor in breast cancer and a promising drug target. Epithelial-mesenchymal transition (EMT) is a critical early step in cancer metastasis. Further understanding of this process may shed light on how to stop the spreading of cancer cells. Androgen-repressed prostate cancer (ARCaP) cell lines representative of the epithelial (ARCaP-E) and mesenchymal (ARCaP-M) phenotypes were used and their secretome was investigated using proteomics approaches. High levels of proteins involved in bone remodeling and extracellular matrix degradation were detected in the ARCaP-M cells, indicative of a bone metastatic phenotype. LC-MS/MS analysis showed that the serine protease granzyme B (GZMB) was 800-fold higher in ARCaP-M conditioned media. Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) and Western blot further showed that GZMB was expressed and translated in ARCaP-M cells and the protein is only detected extracellularly. ARCaP-M cells with the GZMB gene knockdown using RNA interference showed a markedly reduced invasiveness as demonstrated by the Matrigel invasion assay. Our findings indicate a novel role for GZMB in prostate cancer invasion and extracellular matrix degradation. / A Dissertation submitted to the Department of Chemistry and Biochemistry in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / 2019 / November 4, 2019. / Breast cancer, Epithelial-mesenchymal transition, Immune evasion, Metastasis, Prostate Cancer / Includes bibliographical references. / Qing-Xiang Sang, Professor Co-Directing Dissertation; Jinfeng Zhang, Professor Co-Directing Dissertation; Fanxiu Zhu, University Representative; Timothy Logan, Committee Member; Christian Bleiholder, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_752415 |
| Contributors | Burjas Bou-Dargham, Mayassa J. (author), Sang, Qing-Xiang (professor co-directing dissertation), Zhang, Jinfeng (professor co-directing dissertation), Zhu, Fanxiu (university representative), Logan, Timothy M., 1961- (committee member), Bleiholder, Christian (committee member), Florida State University (degree granting institution), College of Arts and Sciences (degree granting college), Department of Chemistry and Biochemistry (degree granting departmentdgg) |
| Publisher | Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text, doctoral thesis |
| Format | 1 online resource (139 pages), computer, application/pdf |
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