Modulation of cancer cell growth and progression by Caveolin-1 in the tumor microenvironment

Caveolin-1 (Cav-1), a major structural component of cell membrane caveolae, is involved in a variety of intracellular signaling pathways as well as transmembrane transport. Cav-1, as a scaffolding protein, modulates signal transduction associated with cell cycle progression, cellular senescence, cell proliferation and death, lipid homeostasis, etc. Cav-1 is also thought to regulate the expression or activity of oncoproteins, such as Src family kinases, H-Ras, protein kinase C, epidermal growth factor, extracellular signal-regulated kinase, and endothelial nitric oxide synthase. Because of its frequent overexpression or mutation in various tumor tissues and cancer cell lines, Cav-1 has been speculated to play a role as an oncoprotein in cancer development and progression. In contrast, Cav-1 may also function as a tumor suppressor, depending on the type of cancer cells and/or surrounding -stromal cells in the tumor microenvironment as well as the stage of tumors.

Prostate-specific markers to identify rare prostate cancer cells in liquid biopsies

Despite improvements in early detection and advances in treatment, patients with prostate cancer continue to die from their disease. Minimal residual disease after primary definitive treatment can lead to relapse and distant metastases, and increasing evidence suggests that circulating tumour cells (CTCs) and bone marrow-derived disseminated tumour cells (BM-DTCs) can offer clinically relevant biological insights into prostate cancer dissemination and metastasis. Using epithelial markers to accurately detect CTCs and BM-DTCs is associated with difficulties, and prostate-specific markers are needed for the detection of these cells using rare cell assays. Putative prostate-specific markers have been identified, and an optimized strategy for staining rare cancer cells from liquid biopsies using these markers is required. The ideal prostate-specific marker will be expressed on every CTC or BM-DTC throughout disease progression (giving high sensitivity) and will not be expressed on non-prostate-cancer cells in the sample (giving high specificity). Some markers might not be specific enough to the prostate to be used as individual markers of prostate cancer cells, whereas others could be truly prostate-specific and would make ideal markers for use in rare cell assays. The goal of future studies is to use sensitive and specific prostate markers to consistently and reliably identify rare cancer cells