Low spinophilin expression enhances aggressive biological behavior of breast cancer

Abstract

Spinophilin, a putative tumor suppressor gene, has been shown to be involved in the pathogenesis of certain types of cancer, but its role has never been systematically explored in breast cancer. In this study, we determined for the first time the expression pattern of spinophilin in human breast cancer molecular subtypes (n = 489) and correlated it with survival (n = 921). We stably reduced spinophilin expression in breast cancer cells and measured effects on cellular growth, apoptosis, anchorage-independent growth, migration, invasion and self-renewal capacity in vitro and metastases formation in vivo. Microarray profiling was used to determine the most abundantly expressed genes in spinophilin-silenced breast cancer cells. Spinophilin expression was significantly lower in basal-like breast cancer (p<0.001) and an independent poor prognostic factor in breast cancer patients (hazard ratio = 1.93, 95% confidence interval: 1.24-3.03; p = 0.004) A reduction of spinophilin levels increased cellular growth in breast cancer cells (p<0.05), without influencing activation of apoptosis. Anchorage-independent growth, migration and self-renewal capacity in vitro and metastatic potential in vivo were also significantly increased in spinophilin-silenced cells (p<0.05). Finally, we identified several differentially expressed genes in spinophilin-silenced cells. According to our data, low levels of spinophilin are associated with aggressive behavior of breast cancer.

Spinophilin in human cancer – molecular mechanisms and clinical relevance

“…Moreover, we generated stably expressing spinophilin-directed shRNA CRC cell lines and studied the influence of spinophilin expression on cellular phenotypes and molecular interactions. Low spinophilin expression levels are significantly associated with poor prognosis in CRC patients (p = 0.038), a finding that is quite similar to a previously reported study [9] . We confirmed that a reduction of spinophilin levels in p53 wild-type HCT116 and p53-mutated Caco-2 cells were associated with an increase of cellular proliferation and also anchorage-independent growth (p < 0.05).…”

“…In addition, growth promoting effects were observed in cell line models and in vivo metastases were promoted. Several potentially differentially expressed genes were discovered by using microarray technology [9] . Taken together, in our studies we evaluated the novel putative tumor suppressor spinophilin in patients with HCC, HNSCC and CRC [4][5][6] .…”

SOX9 is a proliferation and stem cell factor in hepatocellular carcinoma and possess widespread prognostic significance in different cancer types

“…To measure differences in parental adherent growing cells and tumour spheres, which are considered to be enriched of stem/progenitor cancer cells, we established a spheroid growth model as previously described. [ 23 ] In detail, the adherent growing cell lines were dissociated into single cells using trypsin/EDTA and seeded in ultra-low attachment flasks (Corning) using in serum-free McCoy5A medium (SFM). SFM was supplemented with 1xB27 supplement (GIBCO), 20 ng/ml human epidermal growth factor EGF (Peprotech, Rocky Hill, NJ, USA), 20 ng/ml human basic fibroblast growth factor FGF (Peprotech), 20 IU/ml Heparin (Baxter, Vienna, Austria), 4 IU/l insulin actrapid (Novo Nordisk, Vienna, Austria) and 1% antibiotic/antimycotic solution (Sigma-Aldrich, Vienna, Austria).…”

Current Status of Long Non-Coding RNAs in Human Breast Cancer

“…Breast cancer represents a highly heterogeneous disease in terms of clinical outcomes and biological behavior and thus can be classified with various methods into different subtypes [ 2 ]. In recent years, several novel molecular, cellular, tissue- and blood-based prognostic factors have been identified [ 3 , 4 , 5 ]. In routine clinical practice, however, relying on immunohistochemical analysis of the estrogen receptor (ER), progesterone receptor and her2/neu receptor, breast cancer is subdivided into hormone receptor positive, her2/neu receptor positive, and (lack of all three receptors) triple negative [ 6 ].…”