Quantitative and Qualitative Analysis of the Antifungal Activity of Allicin Alone and in Combination with Antifungal Drugs

The antifungal activity of allicin and its synergistic effects with the antifungal agents flucytosine and amphotericin B (AmB) were investigated in Candida albicans (C. albicans). C. albicans was treated with different conditions of compounds alone and in combination (allicin, AmB, flucytosine, allicin + AmB, allicin + flucytosine, allicin + AmB + flucytosine). After a 24-hour treatment, cells were examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM) to measure morphological and biophysical properties associated with cell death. The clearing assay was conducted to confirm the effects of allicin. The viability of C. albicans treated by allicin alone or with one antifungal drug (AmB, flucytosine) in addition was more than 40% after a 24-hr treatment, but the viability of groups treated with combinations of more than two drugs was less than 32%. When the cells were treated with allicin alone or one type of drug, the morphology of the cells did not change noticeably, but when cells were treated with combinations of drugs, there were noticeable morphological changes. In particular, cells treated with allicin + AmB had significant membrane damage (burst or collapsed membranes). Classification of cells according to their cell death phase (CDP) allowed us to determine the relationship between cell viability and treatment conditions in detail. The adhesive force was decreased by the treatment in all groups compare to the control. Cells treated with AmB + allicin had a greater adhesive force than cells treated with AmB alone because of the secretion of molecules due to collapsed membranes. All cells treated with allicin or drugs were softer than the control cells. These results suggest that allicin can reduce MIC of AmB while keeping the same efficacy

The interaction of SKP2 with p27 enhances the progression and stemness of osteosarcoma

Osteosarcoma is a highly aggressive malignancy for which treatment has remained essentially unchanged for years. Our previous studies found that the F-box protein SKP2 is overexpressed in osteosarcoma, acting as a protooncogene; p27(Kip1) (p27) is an inhibitor of cyclin-dependent kinases and a downstream substrate of SKP2-mediated ubiquitination. Overexpression of SKP2 and underexpression of p27 are common characteristics of cancer cells. The SCF(SKP2) E3 ligase ubiquitinates Thr187-phosphorylated p27 for proteasome degradation, which can be abolished by a Thr187Ala knock-in (p27(T187A) KI) mutation. RB1 and TP53 are two major tumor suppressors commonly coinactivated in osteosarcoma. We generated a mouse model with a double knockout (DKO) of Rb1 and Trp53 within cells of the osteoblastic lineage, which developed osteosarcoma with full penetrance. When p27(T187A) KI mice were crossed on to the DKO background, p27(T187A) protein was found to accumulate in osteosarcoma tumor tissues. Furthermore, p27(T187A) promoted apoptosis in DKO tumors, slowed disease progression, and significantly prolonged overall survival. RNA sequencing analysis also linked the SCF(SKP2)–p27(T187A) axis to potentially reduced cancer stemness. Given that RB1 and TP53 loss or coinactivation is common in human osteosarcoma, our study suggests that inhibiting the SKP2–p27 axis may represent a desirable therapeutic strategy for this cancer

Skp2 depletion reduces tumor-initiating properties and promotes apoptosis in synovial sarcoma.

Synovial sarcoma (SS) is an aggressive soft-tissue cancer with a poor prognosis and a propensity for local recurrence and distant metastasis. In this study, we investigated whether S phase kinase-associated protein (Skp2) plays an oncogenic role in tumor initiation, progression, and metastasis of SS. Our study revealed that Skp2 is frequently overexpressed in SS specimens and SS18-SSX transgenic mouse tumors, as well as correlated with clinical stages. Next, we identified that genetic depletion of Skp2 reduced mesenchymal and stemness markers, and inhibited the invasive and proliferative capacities of SS cell lines. Furthermore, Skp2 depletion markedly suppressed the growth of SS xenografts tumors. Treatment of SS cell lines with the skp2 inhibitor flavokawain A (FKA) reduced Skp2 expression in a dose-dependent manner and resulted in cell cycle arrest and apoptosis. FKA also suppressed the invasion and tumor-initiating properties in SS, similar to the effects of Skp2 knockdown. In addition, a combination of FKA and conventional chemotherapy showed a synergistic therapeutic efficacy. Taken together, our results suggest that Skp2 plays an essential role in the biology of SS by promoting the mesenchymal state and cancer stemness. Given that chemotherapy resistance is often associated with cancer stemness, strategies of combining Skp2 inhibitors with conventional chemotherapy in SS may be desirable

Skp2 depletion reduces tumor-initiating properties and promotes apoptosis in synovial sarcoma.

Synovial sarcoma (SS) is an aggressive soft-tissue cancer with a poor prognosis and a propensity for local recurrence and distant metastasis. In this study, we investigated whether S phase kinase-associated protein (Skp2) plays an oncogenic role in tumor initiation, progression, and metastasis of SS. Our study revealed that Skp2 is frequently overexpressed in SS specimens and SS18-SSX transgenic mouse tumors, as well as correlated with clinical stages. Next, we identified that genetic depletion of Skp2 reduced mesenchymal and stemness markers, and inhibited the invasive and proliferative capacities of SS cell lines. Furthermore, Skp2 depletion markedly suppressed the growth of SS xenografts tumors. Treatment of SS cell lines with the skp2 inhibitor flavokawain A (FKA) reduced Skp2 expression in a dose-dependent manner and resulted in cell cycle arrest and apoptosis. FKA also suppressed the invasion and tumor-initiating properties in SS, similar to the effects of Skp2 knockdown. In addition, a combination of FKA and conventional chemotherapy showed a synergistic therapeutic efficacy. Taken together, our results suggest that Skp2 plays an essential role in the biology of SS by promoting the mesenchymal state and cancer stemness. Given that chemotherapy resistance is often associated with cancer stemness, strategies of combining Skp2 inhibitors with conventional chemotherapy in SS may be desirable