Assessment Of Extracellular Matrix Research Articles

Elastin-specific MRI of extracellular matrix-remodelling following hepatic radiofrequency-ablation in a VX2 liver tumor model

Hepatic radiofrequency ablation (RFA) induces a drastic alteration of the biomechanical environment in the peritumoral liver tissue. The resulting increase in matrix stiffness has been shown to significantly influence carcinogenesis and cancer progression after focal RF ablation. To investigate the potential of an elastin-specific MR agent (ESMA) for the assessment of extracellular matrix (ECM) remodeling in the periablational rim following RFA in a VX2 rabbit liver tumor-model, twelve New-Zealand-White-rabbits were implanted in the left liver lobe with VX2 tumor chunks from donor animals. RFA of tumors was performed using a perfused RF needle-applicator with a mean tip temperature of 70 °C. Animals were randomized into four groups for MR imaging and scanned at four different time points following RFA (week 0 [baseline], week 1, week 2 and week 3 after RFA), followed by sacrifice and histopathological analysis. ESMA-enhanced MR imaging was used to assess ECM remodeling. Gadobutrol was used as a third-space control agent. Molecular MR imaging using an elastin-specific probe demonstrated a progressive increase in contrast-to-noise ratio (CNR) (week 3: ESMA: 28.1 ± 6.0; gadobutrol: 3.5 ± 2.0), enabling non-invasive imaging of the peritumoral zone with high spatial-resolution, and accurate assessment of elastin deposition in the periablational rim. In vivo CNR correlated with ex vivo histomorphometry (ElasticaVanGiesson-stain, y = 1.2x − 1.8, R2 = 0.89, p < 0.05) and gadolinium concentrations at inductively coupled mass spectroscopy (ICP-MS, y = 0.04x + 1.2, R2 = 0.95, p < 0.05). Laser-ICP-MS confirmed colocalization of elastin-specific probe with elastic fibers. Following thermal ablation, molecular imaging using an elastin-specific MR probe is feasible and provides a quantifiable biomarker for the assessment of the ablation-induced remodeling of the ECM in the periablational rim.

Assessment of extracellular matrix and tissue derived metabolites in a liquid biopsy for identifying endotypes of metastatic melanoma patients with differential response to immune checkpoint inhibitor treatment.

e14050 Background: The extracellular matrix (ECM) is a major component of tumors. Several recent findings link ECM composition with outcome in cancer patients treated with immune checkpoint inhibitors (ICIs). The aim here was to explore circulating ECM- and tissue-derived metabolites to enable clustering of patients with metastatic melanoma (MM) into putative endotypes and evaluate patient characteristics and outcome when treated with Ipilimumab accordingly. Methods: Serum was collected from MM patients prior to treatment with Ipilimumab (n = 64). Wards hierarchical clustering of patients was based on 15 ECM- and tissue-derived metabolites measured in serum by ELISA. Identified clusters (endotypes) were compared to clinical characteristics and evaluated for associations with disease control rate (DCR), progression free survival (PFS) and overall survival (OS). Results: Three putative endotypes (cluster A, B, C) were identified including 14, 30 and 20 patients, respectively. Overall a stepwise increase in ECM metabolite median levels were detected from C-B-A with the largest absolute change seen from B-A. There was no difference between A, B, and C according to age, gender, lactate dehydrogenase levels, number of metastasized organs and whether patients were treated previously. At follow-up, the DCR was 0%, 60% and 45% in A, B, and C, respectively. Likewise, patients with endotype A had a median PFS/OS time of 69/85 days versus 174/520 and 165/589 days for endotype B and C. In support, endotype A predicted for poor survival outcomes (PFSAvsB+C:HR = 3.9, 95%CI:2.0-7.6, p = 0.0001; OSAvsB+C:HR:2.5, 95%CI:1.2-4.9, p = 0.0108). Conclusions: Hierarchical clustering of MM patients based on 15 ECM- and tissue-derived metabolites measured in a liquid biopsy identifies 3 putative endotypes. One endotype (A) seems to reflect patients with an overall high and differentiated ECM turnover profile. These patients experience poor outcome when treated with Ipilimumab. If validated, this supports a link between ECM remodeling and outcome in cancer patients treated with ICIs.

PRO-C3-levels in patients with HIV/HCV-Co-infection reflect fibrosis stage and degree of portal hypertension.

BackgroundLiver-related deaths represent the leading cause of mortality among patients with HIV/HCV-co-infection, and are mainly related to complications of fibrosis and portal hypertension. In this study, we aimed to evaluate the structural changes by the assessment of extracellular matrix (ECM) derived degradation fragments in peripheral blood as biomarkers for fibrosis and portal hypertension in patients with HIV/HCV co-infection.MethodsFifty-eight patients (67% male, mean age: 36.5 years) with HIV/HCV-co-infection were included in the study. Hepatic venous pressure gradient (HVPG) was measured in forty-three patients. The fibrosis stage was determined using FIB4 -Score. ECM degraded products in peripheral blood were measured using specific ELISAs (C4M, MMP-2/9 degraded type IV collagen; C5M, MMP-2/9 degraded type V collagen; PRO-C3, MMP degraded n-terminal propeptide of type III collagen).ResultsAs expected, HVPG showed strong and significant correlations with FIB4-index (rs = 0.628; p = 7*10−7). Interestingly, PRO-C3 significantly correlated with HVPG (rs = 0.354; p = 0.02), alanine aminotransferase (rs = 0.30; p = 0.038), as well as with FIB4-index (rs = 0.3230; p = 0.035). C4M and C5M levels were higher in patients with portal hypertension (HVPG>5 mmHg).ConclusionPRO-C3 levels reflect liver injury, stage of liver fibrosis and degree of portal hypertension in HIV/HCV-co-infected patients. Furthermore, C4M and C5M were associated with increased portal pressure. Circulating markers of hepatic ECM remodeling might be helpful in the diagnosis and management of liver disease and portal hypertension in patients with HIV/HCV coinfection.