SCUBE1: a promising biomarker in renal cell cancer

Can we use serum SCUBE 1 levels as a biomarker in obstructive sleep apnea hypopnea syndrome?

OBJECTIVE

To examine the SCUBE1 level, a biomarker in vascular biology that could determine the prognosis of cardiovascular events during OSA treatment.

METHODS

In total, 129 patients were included in the study. Thirty were diagnosed with simple snoring and 99 with OSA.

RESULTS

In males, significant correlation was determined between SCUBE1 non-REM AHI, hypopnea index, total apnea index, mean SO2, minimum SO2, and < 90% saturation duration.

CONCLUSION

Serum SCUBE1 levels increased more in male patients with severe OSA compared to other OSA levels, and high serum SCUBE1 levels were found to be associated with lower oxygen levels in OSA patients. The SCUBE1 biomarker can correlate with severe OSA in males. There was a statistically significant difference between OSA groups in terms of SCUBE1 score for male patients (p = 0.002) but not for females (p = 0.498). It is important that future SCUBE1 studies evaluate males vs. females.

SCUBE1 promotes pulmonary artery smooth muscle cell proliferation and migration in acute pulmonary embolism by modulating BMP7

Objectives

After an episode of acute pulmonary embolism (APE), activated platelets have the ability to release various bioactive factors that can stimulate both proliferation and migration of pulmonary artery smooth muscle cells (PASMCs). SCUBE1 has been previously reported to engage in platelet-platelet interactions, potentially contributing to the activation of platelets in early onset thrombi. The purpose of this study was to examine the alterations in SCUBE1 expression in PASMCs after APE, as well as understand the mechanism behind these changes.

Methods

The platelet-rich plasma samples of both APE patients and healthy individuals were collected. A hyperproliferative model of PASMCs was established by using platelet-derived growth factor (PDGF) as a stimulator and various assays were used to investigate how SCUBE1-mediated BMP7 can regulate PDGF-induced PASMC proliferation and migration.

Results

Elevated level of SCUBE1 were observed in platelet-rich plasma from patients with APE and in PASMCs induced by PDGF. SCUBE1 interference ameliorated PDGF-driven cell proliferation and migration, and also downregulated PCNA expression. Additionally, mechanistic studies demonstrated that SCUBE1 could directly bind to bone morphogenetic protein 7 (BMP7) and enhance BMP7 expression, which completely abolished the impact of SCUBE1 silencing on proliferation and migration ability of PASMCs after PDGF treatment.

Conclusion

In the PDGF-induced proliferation of PASMCs, the expression of SCUBE1 and BMP7 was upregulated. Silencing of SCUBE1 impeded PDGF-induced proliferation and migration of PASMCs by restraining BMP7.

Could SCUBE-1 be a marker for subclinical atherosclerosis other than carotid artery intima-media thickness in patients with psoriasis?

BACKGROUND

Psoriasis is a chronic inflammatory disease that is associated with many inflammatory conditions such as atherosclerosis, hypertension, among others. SCUBE-1 is a protein that plays a role in angiogenesis.

OBJECTIVES

The present study aimed to investigate whether SCUBE-1 could indicate subclinical atherosclerosis in psoriatic patients, and to compare SCUBE-1 levels, measurement of carotid artery ıntima-media thickness (CIMT), and metabolic parameters in psoriasis patients and healthy controls.

METHODS

Forty-six patients with psoriasis and 43 healthy controls were included. The severity of the disease was assessed with Psoriasis Area Severity Index (PASI) in the patient group. Levels of SCUBE-1, CRP, lipids, and fasting glucose were measured with the enzyme-linked ımmunosorbent assay (ELISA) method, and CIMT measurements were performed by the same cardiologist.

RESULTS

SCUBE-1 levels and CIMT values were significantly higher in the patient group (for both p < 0.05). Moreover, systolic blood pressure, CRP levels, and waist circumference were higher in the patient group even though both groups had similar BMIs (for all p < 0.05). A positive correlation was found between SCUBE-1 and CIMT values among patients, and multiple regression analyses revealed that SCUBE-1 and CIMT are significantly associated with psoriasis as well.

STUDY LIMITATIONS

A low number of participants and not including any other inflammatory marker related to angiogenesis or atherosclerosis such as VEGF, adiponectin are the main limitations of the present study.

CONCLUSION

Despite the severity of the disease, even in psoriasis patients with mild disease the SCUBE-1 level may be an indicator of subclinical atherosclerosis and indicate the risk of cardiovascular disease in the future.

The biology of SCUBE

The SCUBE [Signal peptide-Complement C1r/C1s, Uegf, Bmp1 (CUB)-Epithelial growth factor domain-containing protein] family consists of three proteins in vertebrates, SCUBE1, 2 and 3, which are highly conserved in zebrafish, mice and humans. Each SCUBE gene encodes a polypeptide of approximately 1000 amino acids that is organized into five modular domains: (1) an N-terminal signal peptide sequence, (2) nine tandem epidermal growth factor (EGF)-like repeats, (3) a large spacer region, (4) three cysteine-rich (CR) motifs, and (5) a CUB domain at the C-terminus. Murine Scube genes are expressed individually or in combination during the development of various tissues, including those in the central nervous system and the axial skeleton. The cDNAs of human SCUBE orthologs were originally cloned from vascular endothelial cells, but SCUBE expression has also been found in platelets, mammary ductal epithelium and osteoblasts. Both soluble and membrane-associated SCUBEs have been shown to play important roles in physiology and pathology. For instance, upregulation of SCUBEs has been reported in acute myeloid leukemia, breast cancer and lung cancer. In addition, soluble SCUBE1 is released from activated platelets and can be used as a clinical biomarker for acute coronary syndrome and ischemic stroke. Soluble SCUBE2 enhances distal signaling by facilitating the secretion of dual-lipidated hedgehog from nearby ligand-producing cells in a paracrine manner. Interestingly, the spacer regions and CR motifs can increase or enable SCUBE binding to cell surfaces via electrostatic or glycan-lectin interactions. As such, membrane-associated SCUBEs can function as coreceptors that enhance the signaling activity of various serine/threonine kinase or tyrosine kinase receptors. For example, membrane-associated SCUBE3 functions as a coreceptor that promotes signaling in bone morphogenesis. In humans, SCUBE3 mutations are linked to abnormalities in growth and differentiation of both bones and teeth. In addition to studies on human SCUBE function, experimental results from genetically modified mouse models have yielded important insights in the field of systems biology. In this review, we highlight novel molecular discoveries and critical directions for future research on SCUBE proteins in the context of cancer, skeletal disease and cardiovascular disease.

CAFs-derived SCUBE1 promotes malignancy and stemness through the Shh/Gli1 pathway in hepatocellular carcinoma

Background

The tumour microenvironment and cirrhotic liver are excellent sources of cancer-associated fibroblasts (CAFs), which participate in carcinogenesis. Thus, it is important to clarify the crosstalk between CAFs and HCC cells and the related mechanism in regulating carcinogenesis.

Methods

Human hepatocellular carcinoma (HCC) tissues and matched adjacent normal tissues were obtained from HCC patients. Immunohistochemistry, Western blotting (WB) and RT–qPCR were performed to detect the expression of SCUBE1. The roles of SCUBE1 in inducing stemness features in HCC cells were explored and investigated in vitro and in vivo. Student’s t tests or Mann–Whitney U tests were used to compare continuous variables, while chi-square tests or Fisher’s exact tests were used to compare categorical variables between two groups.

Results

SCUBE1 was confirmed to be highly expressed in CAFs in HCC and had a strong connection with stemness and a poor prognosis. In addition, CAFs were found to secrete SCUBE1 to enhance the malignancy of HCC cells and increase the proportion of CD133-positive cells. Silencing SCUBE1 expression had the opposite effect. The Shh pathway was activated by SCUBE1 stimulation. Inhibition of cyclopamine partially reversed the stimulating effect of SCUBE1 both in vivo and in vitro. Moreover, based on the RT–qPCR, ELISA and WB results, a high SCUBE1 expression level was found in HCC tissue and serum.

Conclusion

This study revealed that CAFs-derived SCUBE1 can enhance the malignancy and stemness of HCC cells through the Shh pathway. This study aims to provide new perspectives for future HCC studies and provide new strategies for HCC treatment.

The Multifaceted Role of Signal Peptide-CUB-EGF Domain-Containing Protein (SCUBE) in Cancer

Signal peptide, CUB, and EGF-like domain-containing proteins (SCUBE) are secretory cell surface glycoproteins that play key roles in the developmental process. SCUBE proteins participate in the progression of several diseases, including cancer, and are recognized for their oncogenic and tumor suppressor functions depending on the cellular context. SCUBE proteins promote cancer cell proliferation, angiogenesis, invasion, or metastasis, stemness or self-renewal, and drug resistance. The association of SCUBE with other proteins alters the expression of signaling pathways, including Hedgehog, Notch, TGF-β/Smad2/3, and β-catenin. Further, SCUBE proteins function as potential prognostic and diagnostic biomarkers for breast cancer, renal cell carcinoma, endometrial carcinoma, and nasopharyngeal carcinoma. This review presents key features of SCUBE family members, and their structure and functions, and highlights their contribution in the development and progression of cancer. A comprehensive understanding of the role of SCUBE family members offers novel strategies for cancer therapy.

TGF-β superfamily co-receptors in cancer

Transforming growth factor-β (TGF-β) superfamily signaling via their cognate receptors is frequently modified by TGF-β superfamily co-receptors. Signaling through SMAD-mediated pathways may be enhanced or depressed depending on the specific co-receptor and cell context. This dynamic effect on signaling is further modified by the release of many of the co-receptors from the membrane to generate soluble forms that are often antagonistic to the membrane-bound receptors. The co-receptors discussed here include TβRIII (betaglycan), endoglin, BAMBI, CD109, SCUBE proteins, neuropilins, Cripto-1, MuSK, and RGMs. Dysregulation of these co-receptors can lead to altered TGF-β superfamily signaling that contributes to the pathophysiology of many cancers through regulation of growth, metastatic potential, and the tumor microenvironment. Here we describe the role of several TGF-β superfamily co-receptors on TGF-β superfamily signaling and the impact on cellular and physiological functions with a particular focus on cancer, including a discussion on recent pharmacological advances and potential clinical applications targeting these co-receptors.

The relationship of serum SCUBE-1, -2 and -3 levels with clinical findings and ultrasonographic skin thickness in systemic sclerosis patients

AIM

This study aimed to investigate the relationship between the level of serum signal peptide-CUB-EGF domain-containing protein (SCUBE)-1, SCUBE-2 and SCUBE-3 and clinical findings and ultrasonographic skin thickness in systemic sclerosis (SSc).

MATERIAL AND METHODS

Thirty patients who met the American College of Rheumatology/European League against Rheumatism 2013 SSc classification criteria and 44 healthy volunteers who were compatible with the patient group in terms of age and gender were included in the study. Serum SCUBE levels were measured by enzyme-linked immunosorbent assay. Ultrasonographic skin thickness measurements were simultaneously performed.

RESULTS

No significant difference was found between the serum SCUBE levels of SSc patients and serum SCUBE levels of the control group. A negative correlation was detected between serum SCUBE-1 level and forced expiratory volume in 1 second (FEV₁ ). While a positive correlation was detected between serum SCUBE-2 level and the Duruöz Hand Index and serum C4 level, a negative correlation was determined with the forced vital capacity (FVC) value. A negative correlation was determined between serum SCUBE-3 level and echocardiographic pulmonary artery pressure (PAP). A correlation could not be determined between serum SCUBE levels and ultrasonographic skin thickness. However, a positive correlation was observed between ultrasonographic skin thickness and the modified Rodnan skin score.

CONCLUSION

In this study, a correlation was observed between serum SCUBE levels and some clinical and laboratory parameters (FEV₁ , FVC, PAP, C4, and Duruöz Hand Index) in SSc patients. New clinical studies are needed to better understand the contribution of these molecules in the progression and pathogenesis of SSc.

Is SCUBE1 helpful to predict the arterial thrombotic risk in patients with multi-ple myeloma: a preliminary study

BACKGROUND

Signal peptide-CUB-EGF-like domain-containing protein 1 (SCUBE1) is expressed in vascular endothelium and human platelets. SCUBE1 levels are increased in acute arterial thrombosis. Multiple myeloma patients are also at increased risk of arterial thrombotic events. This study aimed to measure SCUBE1 levels in newly diagnosed multiple myeloma patients and to define whether SCUBE1 could be a useful marker determining the arterial thrombotic risk.

METHODS

  SCUBE1 levels of 32 newly diagnosed multiple myeloma patients and 41 healthy control subjects were measured by enzyme-linked immunosorbent assay.

RESULTS

Plasma SCUBE1 levels of multiple myeloma patients and control subjects were 6.22 ± 0.9 and 7.95 ± 1.1 ng/ml, respectively. In the patient group, SCUBE1 levels were significantly lower compared to control subjects (p <0.001).

CONCLUSIONS

SCUBE1 level measuring does not help to predict the arterial thrombotic risk in multiple myeloma patients. The significantly lower levels of SCUBE1 in multiple myeloma patients are likely to be due to defective platelets and/or increased TNF-α cytokines and is another proof of platelet dysfunction seen in these patients. HIPPOKRATIA 2019, 23(1): 21-24.

The Diagnostic Value of FNDC5/Irisin in Renal Cell Cancer

PURPOSES

The aim of this study was to determine the diagnostic significance of fibronectin type III domain containing protein 5 (FNDC5)/Irisin levels in the sera of patients with renal cell cancer.

MATERIALS AND METHODS

In the study, 48 individuals were evaluated. The patient group included 23 subjects diagnosed with renal tumor, and the control group of 25 healthy individuals. Patients diagnosed with renal tumor received surgical treatment consisting of radical or partial nephrectomy. Blood specimens were collected and serum FNDC5/ Irisin and carcinoembryonic antigen (CEA) levels were determined using enzyme-linked immunosorbent assay (ELISA).

RESULTS

FNDC5/irisin and CEA levels in renal cancer patients were significantly higher compared with the control group (p=0.0001, p=0.009, respectively). Also, FNDC5 levels was more sensitive and specific than CEA levels. The best cut-off points for FNDC5/ irisin were >105pg/mL and CEA were >2.67ng/mL for renal cancer.

CONCLUSIONS

FNDC5/Irisin may be used as a diagnostic biomarker for renal cancer.