SCUBE2 inhibits the proliferation, migration and invasion of human non-small cell lung cancer cells through regulation of the sonic hedgehog signaling pathway

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.

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.

Molecular Mechanisms Involving the Sonic Hedgehog Pathway in Lung Cancer Therapy: Recent Advances

According to the latest statistics from the International Agency for Research on Cancer (IARC), lung cancer is one of the most lethal malignancies in the world, accounting for approximately 18% of all cancer-associated deaths. Yet, even with aggressive interventions for advanced lung cancer, the five-year survival rate remains low, at around 15%. The hedgehog signaling pathway is highly conserved during embryonic development and is involved in tissue homeostasis as well as organ development. However, studies have documented an increasing prevalence of aberrant activation of HH signaling in lung cancer patients, promoting malignant lung cancer progression with poor prognostic outcomes. Inhibitors targeting the HH pathway have been widely used in tumor therapy, however, they still cannot avoid the occurrence of drug resistance. Interestingly, natural products, either alone or in combination with chemotherapy, have greatly improved overall survival outcomes for lung cancer patients by acting on the HH signaling pathway because of its unique and excellent pharmacological properties. In this review, we elucidate on the underlying molecular mechanisms through which the HH pathway promotes malignant biological behaviors in lung cancer, as well as the potential of inhibitors or natural compounds in targeting HH signaling for clinical applications in lung cancer therapy.

Estrogen receptor-positive breast cancer survival prediction and analysis of resistance-related genes introduction

Background

In recent years, ER+ and HER2- breast cancer of adjuvant therapy has made great progress, including chemotherapy and endocrine therapy. We found that the responsiveness of breast cancer treatment was related to the prognosis of patients. However, reliable prognostic signatures based on ER+ and HER2- breast cancer and drug resistance-related prognostic markers have not been well confirmed, This study in amied to establish a drug resistance-related gene signature for risk stratification in ER+ and HER2- breast cancer.

Methods

We used the data from The Cancer Genoma Atlas (TCGA) breast cancer dataset and gene expression database (Gene Expression Omnibus, GEO), constructed a risk profile based on four drug resistance-related genes, and developed a nomogram to predict the survival of patients with I-III ER+ and HER2- breast cancer. At the same time, we analyzed the relationship between immune infiltration and the expression of these four genes or risk groups.

Results

Four drug resistance genes (AMIGO2, LGALS3BP, SCUBE2 and WLS) were found to be promising tools for ER+ and HER2- breast cancer risk stratification. Then, the nomogram, which combines genetic characteristics with known risk factors, produced better performance and net benefits in calibration and decision curve analysis. Similar results were validated in three separate GEO cohorts. All of these results showed that the model can be used as a prognostic classifier for clinical decision-making, individual prediction and treatment, as well as follow-up.

Sulforaphane inhibits self-renewal of lung cancer stem cells through the modulation of sonic Hedgehog signaling pathway and polyhomeotic homolog 3

Sulforaphane (SFN), an active compound in cruciferous vegetables, has been characterized by its antiproliferative capacity. We investigated the role and molecular mechanism through which SFN regulates proliferation and self-renewal of lung cancer stem cells. CD133⁺ cells were isolated with MACs from lung cancer A549 and H460 cells. In this study, we found that SFN inhibited the proliferation of lung cancer cells and self-renewal of lung cancer stem cells simultaneously. Meanwhile, the mRNA and protein expressions of Shh, Smo, Gli1 and PHC3 were highly activated in CD133⁺ lung cancer cells. Compared with siRNA-control group, Knock-down of Shh inhibited proliferation of CD133⁺ lung cancer cells, and decreased the protein expression of PHC3 in CD133⁺ lung cancer cells. Knock-down of PHC3 also affected the proliferation and decreased the Shh expression level in CD133⁺ lung cancer cells. In addition, SFN inhibited the activities of Shh, Smo, Gli1 and PHC3 in CD133⁺ lung cancer cells. Furthermore, the inhibitory effect of SFN on the proliferation of siRNA-Shh and siRNA-PHC3 cells was weaker than that on the proliferation of siRNA-control cells. Sonic Hedgehog signaling pathway might undergo a cross-talk with PHC3 in self-renewal of lung cancer stem cells. SFN might be an effective new drug which could inhibit self-renewal of lung cancer stem cells through the modulation of Sonic Hedgehog signaling pathways and PHC3. This study could provide a novel way to improve therapeutic efficacy for lung cancer stem cells.

Anti-hepatoma effect of taccalonolide A through suppression of sonic hedgehog pathway

Taccalonolide A has been reported to have anti-tumour efficiency. However, the underlying mechanism for taccalonolides A therapy of hepatocellular carcinoma (HCC) is still obscure. Cell viability was evaluated by cell counting kit-8 (CCK-8) assay. Apoptosis was determined by flow cytometry. Protein expression of B cell lymphoma (Bcl-2), Bcl-2 associated X (Bax), sonic hedgehog (Shh), Smoothened (Smo) and Gli family zinc finger 1 (Gli1) was analyzed by western blot. The expression of Shh, Smo and Gli1 mRNA was determined using quantitative real-time polymerase chain reaction (qRT-PCR). Results showed that taccalonolide A inhibited cell proliferation, induced apoptosis and cell cycle arrest at the G0/G1 phase, and improved the cytotoxicity of sorafenib in HCC cells. The expressions of Shh, Smo, Gli1 mRNA and protein were decreased after taccalonolide A treatment. More importantly, activation of the Shh pathway attenuated taccalonolide A-induced inhibition on cell viability and promotion on apoptosis and cell cycle arrest in HCC. Also, activation of the Shh pathway neutralized the effect of taccalonolide A on sorafenib cytotoxicity in HCC. We clarified that taccalonolide A suppressed cell viability facilitated apoptosis, and improved the cytotoxicity of sorafenib in HCC by inhibition of the activation of the Shh pathway, providing alternative treatments for HCC.

Circular RNA circ_SETD2 represses breast cancer progression via modulating the miR-155-5p/SCUBE2 axis

Breast cancer (BC) is the leading cause of cancer deaths in women worldwide. Circular RNA circ_SETD2 (circ_SETD2), also termed as hsa_circ_0065173, is reported to be abnormally expressed in BC. Nevertheless, the role and mechanism of circ_SETD2 in BC are unclear. Expression of circ_SETD2, miR-155-5p, and SCUBE2 mRNA was evaluated by quantitative real-time polymerase chain reaction. Cell cycle progression, proliferation, apoptosis, migration, and invasion were determined by flow cytometry, MTT, and transwell assays. The relationship between circ_SETD2 or SCUBE2 and miR-155-5p was verified through a dual-luciferase reporter assay. The role of circ_SETD2 in BC in vivo was confirmed by a xenograft assay. circ_SETD2 and SCUBE2 were downregulated, while miR-155-5p was upregulated in BC tissues and cells. Both circ_SETD2 and SCUBE2 elevation arrested cell cycle progression, inhibited cell proliferation, migration, and invasion, and accelerated cell apoptosis in BC cells. Moreover, circ_SETD2 upregulation repressed BC growth in vivo. Importantly, circ_SETD2 modulated SCUBE2 expression through competitively binding to miR-155-5p in BC cells. Also, the inhibitory impacts of circ_SETD2 enhancement on the malignant behavior of BC cells were restored by miR-155-5p overexpression. Besides, SCUBE2 silencing abolished miR-155-5p downregulation mediated effects on the malignant behavior of BC cells. Therefore, circ_SETD2 curbed BC progression via upregulating SCUBE2 via binding to miR-155-5p.

A 3-gene biomarker signature to predict response to taxane-based neoadjuvant chemotherapy in breast cancer

Breast cancer is the most common cancer in women worldwide, affecting one in eight women in their lifetime. Taxane-based chemotherapy is routinely used in the treatment of breast cancer. The purpose of this study was to develop and validate a predictive biomarker to improve the benefit/risk ratio for that cytotoxic chemotherapy. We explicitly strived for a biomarker that enables secure translation into clinical practice. We used genome-wide gene expression data of the Hatzis et al. discovery cohort of 310 patients for biomarker development and three independent cohorts with a total of 567 breast cancer patients for validation. We were able to develop a biomarker signature that consists of just the three gene products ELF5, SCUBE2 and NFIB, measured on RNA level. Compared to Hatzis et al., we achieved a significant improvement in predicting responders and non-responders in the Hatzis et al. validation cohort with an area under the receiver operating characteristics curve of 0.73 [95% CI, 69%—77%]. Moreover, we could confirm the performance of our biomarker on two further independent validation cohorts. The overall performance on all three validation cohorts expressed as area under the receiver operating characteristics curve was 0.75 [95% CI, 70%—80%]. At the clinically relevant classifier’s operation point to optimize the exclusion of non-responders, the biomarker correctly predicts three out of four patients not responding to neoadjuvant taxane-based chemotherapy, independent of the breast cancer subtype. At the same time, the response rate in the group of predicted responders increased to 42% compared to 23% response rate in all patients of the validation cohorts.

Down-regulation of FOXR2 inhibits hypoxia-driven ROS-induced migration and invasion of thyroid cancer cells via regulation of the hedgehog pathway

Forkhead box R2 (FOXR2), a new member of the FOX family, is involved in a wide range of biological processes such as embryogenesis, differentiation, transformation and metabolic homeostasis. Recently, FOXR2 has been reported to be aberrantly expressed in a variety of cancers and correlated with cancer development. However, the specific role of FOXR2 in thyroid cancer (TC) remains unclear. In this study, we showed that FOXR2 was highly expressed in TC tissues and cell lines. Moreover, down-regulation of FOXR2 inhibited hypoxia-induced reactive oxygen species (ROS) production and migration/invasion of TC cells. We also found that the hedgehog pathway was responsible for the partial mechanisms underlying the inhibitory effect. Taken together, these findings indicated that down-regulation of FOXR2 inhibits hypoxia-driven ROS-induced migration and invasion of TC cells via regulation of the hedgehog pathway. Thus, FOXR2 may hold great potential for TC treatment.

miR-1323 Promotes Cell Migration in Lung Adenocarcinoma by Targeting Cbl-b and Is an Early Prognostic Biomarker

Purpose: MicroRNAs are known to regulate cellular processes in non-small cell lung cancer (NSCLC) cells and predict prognosis. However, identification of specific microRNAs in NSCLC as potential therapeutic targets is controversial. We aim to determine the clinical significance of miR-1323 in the prognosis of patients with lung cancer and the potential mechanism. Patients and methods: A bioinformatics approach was used to screen the importance microRNA in NSCLC through the online GEO database (GSE42425). The relationship between expression level of miR-1323 and overall survival of lung cancer patients was analyzed. Additionally, an independent corhort including 53 NSCLC cases that underwent resection validated the connection between miR-1323 and LUAD patients' overall survival. Next, the function of miR-1323 was studied in vitro by transient transfection. A more in-depth mechanism was studied through luciferase reporter gene experiments. Results: High miR-1323 expression correlated with poor survival in NSCLC patients (P = 0.011), and in lung adenocarcinoma (LUAD) patients (P = 0.015) based on GEO database (GSE42425). In the independent cohort based on our hospital, high miR-1323 expression was associated with LUAD patients (P = 0.025). Moreover, transfection with mimics of miR-1323 showed an increased migratory capacity in LUAD A549 and HCC827 cells. In addition, E3 ubiquitin-protein ligase Casitas B-lineage Lymphoma-b (Cbl-b) was found to be the target genes of miR-1323 and significantly down regulated after mimics of miR-1323 transfection, and high Cbl-b expression predicted better prognosis in NSCLC and LUAD (P = 0.00072 and P = 0.02, respectively). Conclusion: The miR-1323 promoted LUAD migration through inhibiting Cbl-b expression. High miR-1323 expression predicted poor prognosis in LUAD patients.