The role of cystatin C and the angiogenic cytokines VEGF and bFGF in patients with esophageal carcinoma

Comparison of different estimated glomerular filtration rates for monitoring of kidney function in oncology patients

Background

Tyrosine kinase inhibitors (TKIs) are associated with kidney function deterioration. A shift is ongoing towards glomerular filtration rate (GFR) equations based on other protein markers, such as cystatin C (CSTC) and β-trace protein (BTP). We evaluated various GFR equations for monitoring of kidney function in actively treated oncology patients.

Methods

We monitored 110 patients receiving a TKI. Blood and urine were collected during therapy. Serum analysis included creatinine (Cr), CSTC and BTP; for consequent GFR determination. Urine was analysed for protein, albumin, immunoglobulin G, and α-1-microglobulin. A similar analysis was done in a patient subgroup receiving immune checkpoint inhibitors (ICI) as prior or subsequent line of therapy.

Results

Cr remained constant during TKI treatment (P = 0.7753), whereas a significant decrease in CSTC (from week 2 onward, P < 0.0001) and BTP (at weeks 2 and 4, P = 0.0100) were noticed. Consequently, GFR estimations, using CSTC and/or BTP as a biochemical parameter, showed an apparent increase in GFR, whereas this was not observed for Cr-related GFR estimations. As a result, the GFR gap (ΔGFR) was significantly different from week 2 onward between Cr-based and CSTC-based GFR and between BTP-based and CSTC-based GFR. Glomerular damage was noticed with significant increase in urine protein-to-creatinine ratio, albumin-to-creatinine ratio and immunoglobulin G (all P < 0.0001). No change in α-1-microglobulin was seen. ICI treatment had no effect on Cr (P = 0.2262), CSTC (P = 0.7341), and BTP concentrations (P = 0.3592).

Conclusion

GFR equations, in which CSTC is incorporated, fail to correctly estimate the GFR in oncology patients treated with TKIs. As TKI-treated patients show clear signs of glomerular injury, further assessment is needed on how to correctly monitor the kidney function in actively treated oncology patients.

Obesity-Induced Increase in Cystatin C Alleviates Tissue Inflammation

We recently demonstrated that removal of one kidney (uninephrectomy [UniNx]) in mice reduced high-fat diet (HFD)-induced adipose tissue inflammation, thereby improving adipose tissue and hepatic insulin sensitivity. Of note, circulating cystatin C (CysC) levels were increased in UniNx compared with sham-operated mice. Importantly, CysC may have anti-inflammatory properties, and circulating CysC levels were reported to positively correlate with obesity in humans and as shown here in HFD-fed mice. However, the causal relationship of such observation remains unclear. HFD feeding of CysC-deficient (CysC knockout [KO]) mice worsened obesity-associated adipose tissue inflammation and dysfunction, as assessed by proinflammatory macrophage accumulation. In addition, mRNA expression of proinflammatory mediators was increased, whereas markers of adipocyte differentiation were decreased. Similar to findings in adipose tissue, expression of proinflammatory cytokines was increased in liver and skeletal muscle of CysC KO mice. In line, HFD-induced hepatic insulin resistance and impairment of glucose tolerance were further aggravated in KO mice. Consistently, chow-fed CysC KO mice were more susceptible to lipopolysaccharide-induced adipose tissue inflammation. In people with obesity, circulating CysC levels correlated negatively with adipose tissue Hif1α as well as IL6 mRNA expression. Moreover, healthy (i.e., insulin-sensitive) subjects with obesity had significantly higher mRNA expression of CysC in white adipose tissue. In conclusion, CysC is upregulated under obesity conditions and thereby counteracts inflammation of peripheral insulin-sensitive tissues and, thus, obesity-associated deterioration of glucose metabolism.

Cystatin C Expression is Promoted by VEGFA Blocking, With Inhibitory Effects on Endothelial Cell Angiogenic Functions Including Proliferation, Migration, and Chorioallantoic Membrane Angiogenesis

Background Vascular development, including vasculogenesis and angiogenesis, is involved in many diseases. Cystatin C ( CST 3) is a commonly used marker of renal dysfunction, and we have previously reported that its expression level is associated with variations in the gerbil circle of Willis. Thus, we hypothesized that CST 3 may affect endothelial function and angiogenic capacity. In the current study, we sought to determine the influence of CST 3 on endothelial function and explore its potential regulatory pathway. Methods and Results We analyzed CST 3 and vascular endothelial growth factor A ( VEGFA) levels in different developmental stages of gerbils using ELISA s and immunofluorescence (to examine the relationship between CST 3 and VEGFA . We used a real-time cell analyzer, cytotoxicity assays, and the chorioallantoic membrane assay to investigate the function of CST 3 in endothelial cells and the chorioallantoic membrane. Additionally, we used Western blotting to explore the downstream targets of CST 3. The expression levels of both CST 3 and VEGFA were at their highest on day 10 of the embryonic stage. CST 3 inhibited endothelial cell proliferation, migration, tube formation, and permeability, as well as vascular development in the chorioallantoic membrane. Blocking of VEGFA dose-dependently increased CST 3 expression in arterial and venous endothelial cells. Furthermore, overexpression and knockdown of CST 3 significantly affected the protein levels of p53 and CAPN10 (calpain 10), suggesting that CST 3 might play a role in vascular development through these proteins. Conclusions CST 3 may be associated with vascular development and angiogenesis, and this effect could be promoted by blocking VEGFA .

Pretreatment Serum Cystatin C Levels Predict Renal Function, but Not Tumor Characteristics, in Patients with Prostate Neoplasia

To evaluate the role of Cystatin C (Cys-C) in tumorigenesis and progression of prostate cancer (PCa), we retrospectively collected the clinical information from the records of 492 benign prostatic hyperplasia (BPH), 48 prostatic intraepithelial neoplasia (PIN), and 173 PCa patients, whose disease was newly diagnosed and histologically confirmed. Pretreatment serum Cys-C levels were compared across the various groups and then analyzed to identify relationships, if any, with clinical and pathological characteristics of the PCa patient group. There were no significant differences in serum Cys-C levels among the three groups (P > 0.05). In PCa patients with normal SCr levels, patient age was correlated with serum Cys-C level (P ≤ 0.001) but did not correlate with alkaline phosphatase (AKP), lactate dehydrogenase (LDH), prostate specific antigen (PSA), Gleason score, or bone metastasis status (P > 0.05). Age and SCr contributed in part to the variations in serum Cys-C levels of PCa patients (r = 0.356, P ≤ 0.001; r = 0.520, P ≤ 0.001). In conclusion, serum Cys-C levels predict renal function in patients with prostate neoplasia, but were not a biomarker for the development of prostate neoplasia, and were not correlated with the clinicopathological characteristics of PCa.

Arteriosclerotic Changes after Intravitreal Injections of Anti-Vascular Endothelial Growth Factor Drugs in Patients with Exudative Age-Related Macular Degeneration

PURPOSE

The aim of this study was to determine whether multiple intravitreal injections of anti-vascular endothelial growth factor (VEGF) drugs for age-related macular degeneration (AMD) exacerbate systemic arteriosclerosis, using the cardio-ankle vascular index (CAVI) and intima-media thickness (IMT).

METHODS

We analyzed the data of 45 AMD patients who received intravitreal injections of anti-VEGF drugs (ranibizumab and/or aflibercept) and underwent systemic evaluations at baseline and after treatment. Reevaluation was conducted at ≥12 months from the initial treatment.

RESULTS

The total number of intravitreal injections of overall anti-VEGF drugs was significantly correlated with x0394;serum cystatin C. The cumulative number of aflibercept injections was identified as an independent protective factor for x0394;CAVI. An increase in the cumulative number of intravitreal injections of overall anti-VEGF drugs was identified as a protective factor for x0394;mean IMT.

CONCLUSION

Repeated intravitreal injections of an anti-VEGF drug for AMD may lead to morphological and functional changes in large arteries.

Cystatin C, chronic kidney disease and retinopathy in adults without diabetes

BACKGROUND

Serum cystatin C, a novel marker of renal function has been shown to be superior to serum creatinine in predicting renal function decline and adverse outcomes of chronic kidney disease (CKD). Our aim was to investigate the association between cystatin C and retinopathy in adults without diabetes.

METHODS

We examined 1725 Indian adults, aged 40-80 years who participated in the Singapore Indian Eye Study (2007-2009) and were free of diabetes mellitus. CKD was defined as an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2) determined from serum cystatin C (CKD-eGFRcys, n = 199), and serum creatinine (CKD-eGFRcr, n = 81). Retinopathy was assessed from digital fundus photographs of both eyes by trained graders using the modified Airlie House classification. The associations of CKD defined by the two markers alone and in combination (confirmed CKD, eGFRcr <60 and eGFRcys <60, n = 58) with retinopathy were examined using logistic regression models adjusted for potential confounding factors including preexisting cardiovascular disease and albuminuria.

RESULTS

The prevalence of retinopathy among those with CKD-eGFRcr and CKD-eGFRcys was 9.9% and 8.5%, respectively. In separate models, the associations of retinopathy with both CKD-eGFRcys (odds ratio (OR) (95% confidence interval (CI)) = 2.18 (1.14-4.16)) and CKD-eGFRcr were significant (OR (95% CI) = 2.63 (1.10-6.28)). In models including both markers, compared to optimal kidney function (eGFRcr ≥60 and eGFRcys ≥60), confirmed CKD was associated with a fourfold higher odds of retinopathy (OR (95% CI) = 4.01 (1.52-10.60)).

CONCLUSIONS

In a population-based sample of Indian adults without diabetes, CKD defined by both cystatin C and creatinine was strongly associated with retinopathy.

Selection of genes associated with variations in the Circle of Willis in gerbils using suppression subtractive hybridization

Deformities in the Circle of Willis (CoW) can significantly increase the risk of cerebrovascular disease in humans. However, the molecular mechanisms underlying these deformities have not been understood. Based on our previous studies, variations in the CoW of gerbils are hereditary. A normal CoW is observed in approximately 60% of gerbils, a percentage that also applies to humans. Thus, gerbil is an ideal experimental model for studying variations in the CoW. To study the mechanisms underlying these variations, we selected genes associated with different types of the CoW using suppression subtractive hybridization (SSH). After evaluating the efficiency of SSH using quantitative real-time polymerase chain reaction (qPCR) on subtracted and unsubtracted cDNA and Southern blotting on SSH PCR products, 12 SSH libraries were established. We identified 4 genes (CST3, GNAS, GPx4 and PFN2) associated with variations in the CoW. These genes were identified with qPCR and Western blotting using 70 expressed sequence tags from the SSH libraries. Cloning and sequencing allowed us to demonstrate that the 4 genes were closely related to mouse genes. We may assume that these 4 genes play an important role in the development of variations in the CoW. This study provides a foundation for further research of genes related to development of variations in the CoW and the mechanisms of dysmorphosis of cerebral vessels.

Systematic review and meta-analysis of tumor biomarkers in predicting prognosis in esophageal cancer

BACKGROUND

Esophageal cancer (EC) is a frequently occurring cancer with poor prognosis despite combined therapeutic strategies. Many biomarkers have been proposed as predictors of adverse events. We sought to assess the prognostic value of biomarkers in predicting the overall survival of esophageal cancer and to help guide personalized cancer treatment to give patients the best chance at remission.

METHODS

We conducted a systematic review and meta-analysis of the published literature to summarize evidence for the discriminatory ability of prognostic biomarkers for esophageal cancer. Relevant literature was identified using the PubMed database on April 11, 2012, and conformed to the REMARK criteria. The primary endpoint was overall survival and data were synthesized with hazard ratios (HRs).

RESULTS

We included 109 studies, exploring 13 different biomarkers, which were subjected to quantitative meta-analysis. Promising markers that emerged for the prediction of overall survival in esophageal squamous cell cancer included VEGF (18 eligible studies, n=1476, HR=1.85, 95% CI, 1.55-2.21), cyclin D1 (12 eligible studies, n=1476, HR=1.82, 95% CI, 1.50-2.20), Ki-67 (3 eligible studies, n=308, HR=1.11, 95% CI, 0.70-1.78) and squamous cell carcinoma antigen (5 eligible studies, n=700, HR=1.28, 95% CI, 0.97-1.69); prognostic markers for esophageal adenocarcinoma included COX-2 (2 eligible studies, n=235, HR=3.06, 95% CI, 2.01-4.65) and HER-2 (3 eligible studies, n=291, HR=2.15, 95% CI, 1.39-3.33); prognostic markers for uncategorized ECs included p21 (9 eligible studies, n=858, HR=1.27, 95% CI, 0.75-2.16), p53 (31 eligible studies, n=2851, HR=1.34, 95% CI, 1.21-1.48), CRP (8 eligible studies, n=1382, HR=2.65, 95% CI, 1.64-4.27) and hemoglobin (5 eligible studies, n=544, HR=0.91, 95% CI, 0.83-1.00).

CONCLUSIONS

Although some modest bias cannot be excluded, this review supports the involvement of biomarkers to be associated with EC overall survival.

Prognostic value of vascular endothelial growth factor expression in patients with esophageal cancer: a systematic review and meta-analysis

BACKGROUND

VEGF is a prime mediator of tumorigenesis and metastasis. Various studies assessing the prognostic value of VEGF in patients with esophageal cancer remain controversial. This study aims to comprehensively and quantitatively summarize the evidence on the suitability of VEGF to predict patients' survival.

METHODS

Searches were applied to PubMed and EMBASE until December 31, 2011, without language restrictions. Studies were assessed for quality using REMARK (Reporting recommendations for tumor MARKer prognostic studies). Data were collected comparing overall survival in patients with high VEGF level with those with low level. We conducted a systematic review of 31 studies (n = 2,387 patients) and completed a meta-analysis of 30 studies (n = 2,345 patients) that correlated VEGF levels with overall survival. Data were synthesized with HRs.

RESULTS

The estimated risk of death was 1.82-fold greater in patients with high VEGF expression [95% confidence interval (CI), 1.58-2.08]. The heterogeneity was not significant (P = 0.130) between studies. High VEGF expression was associated with worse survival in esophageal squamous cell carcinoma (HR, 1.81; 95% CI, 1.57-2.10) and there was no significance in between-study heterogeneity (P = 0.185). Data collected were not sufficient to determine the prognostic value of VEGF in patients with esophageal adenocarcinoma.

CONCLUSIONS

In this meta-analysis, elevated VEGF expression was associated with poor survival in patients with esophageal cancer but not esophageal adenocarcinoma.

IMPACT

These results support further investigation of VEGF expression for predicting poor survival in patients with esophageal carcinoma and may have implications for treatments directed at inhibiting VEGF-mediated angiogenesis.

Expression of cystatin C in human esophageal cancer

AIMS AND BACKGROUND

Cystatin C is a member of the cysteine protease inhibitors and its function is to decrease protease activity. A recent study showed that it was aberrantly expressed in many malignant tumors in association with tumor invasion and metastasis. We attempted to detect its expression in esophageal cancer tissues and adjacent reparative normal tissues.

METHODS AND DESIGN

Samples of cancers and non-cancerous esophageal tissues were obtained as matched pairs from 30 surgery patients with esophageal cancer and paraffin embedded. The expression of cystatin C in tissues was investigated by immunohistochemistry. Fisher's exact test was used to analyze the relationship between esophageal cancer tissues and adjacent normal tissues. Furthermore, mRNA was extracted, and reverse transcriptase polymerase chain reaction was performed.

RESULTS

The intensity of cystatin C immunostaining in tumor tissues was increased compared to that of adjacent normal tissues. mRNA expression of the cystatin C gene was greater in esophageal cancer than in normal tissues (P <0.05).

CONCLUSIONS

Our results indicate that cystatin C may play an important role in the pathogenesis and metastasis of esophageal cancer.

Activation of growth factor receptors in esophageal cancer--implications for therapy

Esophageal cancer is a highly aggressive disease and is the seventh most common cause of cancer-related death in the western world. Worldwide, it ranks as the sixth most frequent cause of cancer death. Despite advances in surgical techniques and treatment, the prognosis of esophageal cancer remains poor, with very few long-term survivors. The need for novel strategies to detect esophageal cancer earlier and to improve current therapy is urgent. It is well established that growth factors and growth factor receptor-mediated signaling pathways are important components of the transformation process in many forms of cancer, including esophageal cancer. With the recent advances in drug development, there are emerging possibilities to use growth factor signal transduction pathways in targeted therapy. This review provides a summary of the role of growth factors and their receptors in esophageal cancer and discusses their potential roles as biomarkers and as targets in therapy.