A PSP94-derived Peptide PCK3145 inhibits MMP-9 Secretion and Triggers CD44 Cell Surface Shedding: Implication in Tumor Metastasis

Purpose: PCK3145 is a synthetic peptide corresponding to amino acids 31–45 of prostate secretory protein 94, which can reduce experimental skeletal metastases and prostate tumor growth in vivo. Part of its biological action involves the reduction of circulating plasma matrix metalloproteinase (MMP)-9, a crucial mediator in extracellular matrix (ECM) degradation during tumor metastasis and cancer cell invasion. The antimetastatic mechanism of action of PCK3145 is however, not understood. Experimental design: HT-1080 fibrosarcoma cells were treated with PCK3145, and cell lysates used for immunoblot analysis of small GTPase RhoA and membrane type (MT)1-MMP protein expression. Conditioned media was used to monitor soluble MMP-9 gelatinolytic activity by zymography and protein expression by immunoblotting. RT-PCR was used to assess RhoA, MT1-MMP, MMP-9, RECK, and CD44 gene expression. Flow cytometry was used to monitor cell surface expression of CD44 and of membrane-bound MMP-9. Cell adhesion was performed on different purified ECM proteins, while cell migration was specifically performed on hyaluronic acid (HA). Results: We found that PCK3145 inhibited HT-1080 cell adhesion onto HA, laminin-1, and type-I collagen suggesting the common implication of the cell surface receptor CD44. In fact, PCK3145 triggered the shedding of CD44 from the cell surface into the conditioned media. PCK3145 also inhibited MMP-9 secretion and binding to the cell surface. This effect was correlated to increased RhoA and MT1-MMP gene and protein expression. Conclusions: Our data suggest that PCK3145 may antagonize tumor cell metastatic processes by inhibiting both MMP-9 secretion and its potential binding to its cell surface docking receptor CD44. Such mechanism may involve RhoA signaling and increase in MT1-MMP-mediated CD44 shedding. Together with its beneficial effects in clinical trials, this is the first demonstration of PCK3145 acting as a MMP secretion inhibitor. *These authors contributed equally to this work.     

Modulation of melanoma cell phospholipid metabolism in response to heat shock protein 90 inhibition

Molecular chaperone heat shock protein 90 (Hsp90) inhibitors are promising targeted cancer therapeutic drugs, with the advantage that they deplete multiple oncogenic client proteins and modulate all the classical hallmarks of cancer. They are now in clinical trial and show potential for activity in melanoma and other malignancies. Here we explore the metabolic response to Hsp90 inhibition in human melanoma cells using magnetic resonance spectroscopy. We show that, concomitant with growth inhibition and re-differentiation, Hsp90 inhibition in human melanoma cells is associated with increased glycerophosphocholine content. This was seen with both the clinical geldanamycin-based Hsp90 drug 17-AAG and the structurally dissimilar Hsp90 inhibitor CCT018159. The effect was noted in both BRAF mutant SKMEL28 and BRAF wildtype CHL-1 melanoma cells. Elevated content of the -CH2+CH3 fatty acyl chains and cytoplasmic mobile lipid droplets was also observed in 17-AAG-treated SKMEL28 cells. Importantly, the phospholipase A2 inhibitor bromoenol lactone prevented the rise in glycerophosphocholine seen with 17-AAG, suggesting a role for phospholipase A2 activation in the Hsp90 inhibitor-induced metabolic response. Our findings provide a basis for using metabolic changes as non-invasive indicators of Hsp90 inhibition and potentially as biomarkers of anticancer activity with Hsp90 drugs in malignant melanoma and possibly in other cancers.     

Rare mass of the anterior mediastinum: Thymolipomas

Thymolipoma is a rare benign neoplasm of the thymus containing both mature adipose tissue and thymic tissue. We report a case of a 34‐year‐οld man, presenting a mass of the anterior mediastinum, the radiology investigation and operatory piece diagnosed a thymolipoma.This study highlights the clinical diagnostic and therapeutic features as well as the evolutionary characteristics of this entity.     

Value of hematological parameters for predicting patients with severe coronavirus disease 2019: a real-world cohort from Morocco

ObjectiveCoronavirus disease 2019 (COVID-19) is a viral disease caused by severe acute respiratory syndrome coronavirus 2. The clinical manifestations and the evolution of patients with COVID-19 are variable. In addition to respiratory involvement, COVID-19 leads to systemic involvement and can affect the hematopoietic system. This study aimed to evaluate the prognostic value of hematological and hemocytometric parameters in predicting the severity of patients with COVID-19.MethodsWe performed a retrospective study at Mohammed VI university Hospital from 1 March to 11 November 2020. We collected demographic characteristics and hematological findings of incident COVID-19 cases.ResultsA total of 245 patients were included in our study. We found that the rate of lymphopenia was significantly reduced in patients who were severely affected by COVID-19. Additionally, the rate of neutrophilia, the neutrophil side fluorescence light signal, monocyte fluorescent intensity, monocyte size, the neutrophil-to-lymphocyte ratio, the platelet-to-lymphocyte ratio, and the lymphocyte-to-monocyte ratio were significantly elevated in patients who were severely affected by COVID-19.ConclusionsThese results are consistent with the literature regarding the predictive value of these markers. A prospective validation in a large population with a longer follow-up is required.     

The long-term effect of switching from cyclosporin A to mycophenolate mofetil in chronic renal graft dysfunction compared with conventional management.

BACKGROUND: To overcome toxicity of calcineurin inhibitors, recent trials have proposed substituting cyclosporin (CysA) with mycophenolate mofetil (MMF). No data concerning the long-term side effects and long-term renal outcome of this strategy have been published. METHODS: We retrospectively compared 39 renal transplant patients with chronic graft dysfunction who were subjected to CysA to MMF substitution (group 1) with 39 matched renal transplant patients who were continued on conventional management (group 2). The mean serum creatinine and the slope of deterioration of renal function before the date of the therapeutic intervention (T(0)) were similar in both groups. Follow-up in both groups was 76 +/- 42 months before T(0) and 44 +/- 11 months after T(0). RESULTS: In group 1, conversion was associated with a decrease of mean serum creatinine concentrations from 192 to 172 micro mol/l at 1 year (P = 0.004) and 159 micro mol/l at 3 years (P < 0.003) after T(0), whereas it remained unchanged in group 2. The systolic blood pressure decreased in group 1 from 155 mmHg before T(0) to 145 mmHg at 1 year (P < 0.01) and 133 mmHg at 3 years (P < 0.001) without any increase of the antihypertensive drug, whereas it did not change in group 2. Lipid profile tended to improve in group 1 after T(0) and was unchanged in group 2. None of the patients in group 1 developed acute rejection after T(0), whereas two acute rejections occurred in group 2. Graft survival, however, was similar in both groups. In group 1, several side effects occurred related to MMF treatment, and led to its discontinuation in two cases and the reduction of its dose for 18 patients (64%). CONCLUSION: CysA/MMF substitution improves renal function and blood pressure in chronic allograft dysfunction when compared with conventional management. However, CysA/MMF substitution is associated with a high rate of MMF-related side effects, requiring modulation of its dose.     

Targeting soluble Abeta peptide with Tramiprosate for the treatment of brain amyloidosis

Amyloid beta-peptide (Abeta) is a major constituent of senile plaques in Alzheimer's disease (AD). Neurotoxicity results from the conformational transition of Abeta from random-coil to beta-sheet and its oligomerization. Among a series of ionic compounds able to interact with soluble Abeta, Tramiprosate (3-amino-1-propanesulfonic acid; 3APS; Alzhemedtrade mark) was found to maintain Abeta in a non-fibrillar form, to decrease Abeta(42)-induced cell death in neuronal cell cultures, and to inhibit amyloid deposition. Tramiprosate crosses the murine blood-brain barrier (BBB) to exert its activity. Treatment of TgCRND8 mice with Tramiprosate resulted in significant reduction (approximately 30%) in the brain amyloid plaque load and a significant decrease in the cerebral levels of soluble and insoluble Abeta(40) and Abeta(42) (approximately 20-30%). A dose-dependent reduction (up to 60%) of plasma Abeta levels was also observed, suggesting that Tramiprosate influences the central pool of Abeta, changing either its efflux or its metabolism in the brain. We propose that Tramiprosate, which targets soluble Abeta, represents a new and promising therapeutic class of drugs for the treatment of AD.