Vasohibin 2 promotes human luminal breast cancer angiogenesis in a non-paracrine manner via transcriptional activation of fibroblast growth factor 2

VASH2 enhances KIF3C-mediated EGFR-endosomal recycling to promote aggression and chemoresistance of lung squamous cell carcinoma by increasing tubulin detyrosination

Lung squamous cell carcinoma (LUSC) is associated with high mortality and has few therapeutic options. Chemotherapy remains the main treatment for LUSC patients, but multi-drug resistance has become the dominant challenge in the failure of chemotherapy in various cancers. Therefore, the effective therapeutic strategy for LUSC patients is an urgent unmet need. Here, we found vasohibin-2 (VASH2) was a prognostic biomarker for LUSC patients, and VASH2 promoted the malignant biological behaviors of LUSC cells and chemoresistance by increasing the detyrosination of α-tubulin. The high level of detyrosinated-tubulin was negatively associated with patient prognosis. Blocking the tubulin carboxypeptidase (TCP) activity of VASH2 inhibited the xenograft tumor growth and improved the treatment efficacy of paclitaxel in vivo. Results revealed that VASH2-induced increase in tubulin detyrosination boosted the binding of kinesin family member 3C (KIF3C) to microtubules and enhanced KIF3C-dependent endosomal recycling of EGFR, leading to the prolonged activation of PI3K/Akt/mTOR signaling. This study demonstrated that VASH2 was not only a prognostic biomarker but also a promising therapeutic target in LUSC, which offers a novel insight that combination of chemotherapy and EpoY, a TCP inhibitor, may be a promising treatment strategy for LUSC patients.

IL-35 enhances angiogenic effects of small extracellular vesicles in breast cancer

As an indispensable process for breast cancer metastasis, tumour angiogenesis requires a tight interaction between cancer cells and endothelial cells in tumour microenvironment. Here, we explored the participation of small extracellular vesicles (sEVs) derived from breast cancer cells in modulating angiogenesis and investigated the effect of IL-35 in facilitating this process. Firstly, we characterized breast cancer cells-derived sEVs untreated or treated with IL-35 and visualized the internalization of these sEVs by human umbilical vein endothelial cells (HUVECs). Breast cancer cells-derived sEVs promoted endothelial cell proliferation through facilitating cell cycle progression and enhanced capillary-like structures formation and microvessel formation. Subsequent results proved that IL-35 further reinforced the angiogenic effect induced by breast cancer cells-derived sEVs. Moreover, sEVs from breast cancer cells significantly enhanced tumour growth and microvessel density in breast tumour-bearing mice model. Microarray analysis showed that IL-35 might alter the mRNA profiles of sEVs and activate the Ras/Raf/MEK/ERK signalling pathway. These findings demonstrated that IL-35 indirectly promoted angiogenesis in breast cancer through regulating the content of breast cancer cells-derived sEVs, which could be internalized by HUVECs.

The Construction of Retinal Pigment Epithelium Sheets with Enhanced Characteristics and Cilium Assembly Using iPS Conditioned Medium and Small Incision Lenticule Extraction Derived Lenticules

In vitro generation of a functional retinal pigment epithelium (RPE) monolayer sheet is useful and promising for RPE cell therapy. Here, for the first time, we used induced pluripotent stem (iPS) supernatant as the conditioned medium (iPS-CM) and femtosecond laser intrastromal lenticule (FLI-lenticule) as a scaffold to construct an engineered RPE sheet. There are significant enhancements in RPE cell density, transepithelial electrical resistance (TER) and inhibitions of ultraviolet C (UVC)-irradiated apoptosis when RPE cells are cultured in iPS supernatant/Dulbecco's modified Eagle's medium (DMEM)-F12 of 1/2 (iPS-CM) compared with those in normal medium (NM, DMEM-F12). Using the assay of a panel of cytokines, combined with transcriptome and protein analyses, we discover that iPS-CM contains high levels of platelet-derived growth factor AA (PDGF-AA), insulin-like growth factor binding protein (IGFBP)-2, transforming growth factor (TGF)-α and IGFBP-6, which are responsible for the upregulation of gene and protein markers with RPE phenotypes and downregulation of gene and protein markers with epithelial-mesenchymal transition (EMT) phenotypes for RPE cells in iPS-CM when compared to those in NM. Moreover, compared to cultures on tissue culture plates (TCP), RPE cells on FLI-lenticule display more microvilli and cilium in accordance with the results in terms of RNA-Seq data, quantitative polymerase chain reaction (qPCR) expression, immunofluorescence staining, and western blot assays. Furthermore, acellular FLI-lenticule exhibits biocompatibility after rabbit subretinal implantation by 30 days through electroretinography and histological examination. Thus, we determined that engineered RPE sheets treated by iPS-CM in conjunction with FLI-lenticule scaffold aid in enhanced RPE characteristics and cilium assembly. Such a strategy to construct RPE sheets is a promising avenue for developing RPE cell therapy, disease models and drug screening tools. STATEMENT OF SIGNIFICANCE: In vitro generation of a functional RPE monolayer sheet is useful and promising for RPE cell therapy. Here, we constructed engineered RPE sheets treated by iPS-CM in conjunction with FLI-lenticule scaffolds to help in enhanced RPE characteristics and cilium assembly. Such a strategy to generate RPE sheets is a promising avenue for developing RPE cell therapy, disease models and drug screening tools.

PRC1 gene silencing inhibits proliferation, invasion, and angiogenesis of retinoblastoma cells through the inhibition of the Wnt/β-catenin signaling pathway

Retinoblastoma is an ocular malignancy occurring in childhood. The current study evaluates the ability of silenced PRC1 on retinoblastoma cell proliferation, and angiogenesis via the Wnt/β-catenin signaling pathway. A total of 36 cases of retinoblastoma tissues (n = 36) and normal retinal tissues (n = 10) were selected in the current study. Retinoblastoma cells presenting with the high PRC1 messenger RNA (mRNA) expression were selected among the WERI-Rb-1, HXO-RB44, Y79, SO-Rb50, and SO-Rb70 cells lines, and were transfected with siRNA-PRC1 and LiCl (the activator of the Wnt/β-catenin pathway). The expressions of PRC1, VEGF, Wnt1, β-catenin, CyclinD1, extent of β-catenin, and GSK-3β phosphorylation were evaluated. Cell proliferation, cell-cycle distribution, and cell invasion of retinoblastoma cells were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, and Transwell assay. The angiogenesis of retinoblastoma cells was detected by tube formation assay. HXO-RB44 and WERI-Rb-1 cells were selected owing to the highest PRC1 mRNA expression. Meanwhile, PRC2 gene silencing presented lower expression levels of PRC1, VEGF, Wnt1, β-catenin, CyclinD1, extent of β-catenin and GSK-3β phosphorylation, decreased proliferation and invasion abilities, extended G0/G1 phase, and shortened S and G2/M phases of HXO-RB44 and WERI-Rb-1 cells, suggesting the silenced PRC2 inactivated Wnt/β-catenin pathway, so as to further restrain the retinoblastoma cell proliferation, invasion, and angiogenesis. These results support the view that PRC1 gene silencing could suppress the proliferation, and angiogenesis of retinoblastoma cells by repressing the Wnt/β-catenin pathway.

Vasohibin 2 promotes malignant behaviors of pancreatic cancer cells by inducing epithelial-mesenchymal transition via Hedgehog signaling pathway

Background

Based on previous findings, we hypothesized that Vasohibin 2 (VASH2) protein may induce epithelial‐mesenchymal transition (EMT) of pancreatic cancer (PC) cells by promoting the malignant behaviors of these cells. The present study aimed to test this hypothesis and explore the possible mechanisms involved.

Methods

The expression of VASH2 in PC tissues and cell lines was detected by quantitative real‐time PCR and Western blot. PC cells with overexpression or knockdown of VASH2 were used to examine the involvement of VASH2 in EMT by detecting the expression of epithelial (E‐cadherin) and mesenchymal (vimentin) markers and EMT‐related transcription factor ZEB1/2, in gemcitabine resistance and tumor cell invasion by apoptosis and invasion assays, and in cancer stem cell‐like phenotypes by detecting the proportion of CD24⁺CD44⁺ and side population (SP) cells in PC cells with flow cytometry. The impact of VASH2 overexpression and knockdown on components of the Hedgehog signaling pathway was also assessed.

Results

We found that VASH2 was highly expressed in PC tissues and cells. It promoted the EMT of PC cells by altering ZEB1/2 expression. VASH2 also stimulated invasion and chemotherapeutic resistance of PC cells and increased the proportion of cancer stem‐like cells in PC cells. VASH2 did so by upregulating the expression of multiple molecules in the Hedgehog signaling pathway of PC cells.

Conclusion

VASH2 promotes malignant behaviors of PC cells by inducing EMT via activation of the Hedgehog signaling pathway.

KIF26B promotes cell proliferation and migration through the FGF2/ERK signaling pathway in breast cancer

BACKGROUND

Many studies have suggested that high KIF26B expression is directly linked to poor prognostic outcomes in breast cancer. However, the exact role of KIF26B in breast cancer progression is not fully understood. In this study, we aimed to explore the function and mechanism of KIF26B in breast cancer progression.

METHODS

Quantitative real-time PCR and immunohistochemistry analysis were used to detect KIF26B expression in breast cancer cell lines and patient samples. Cell proliferation was assessed by CCK-8 assay, and cell migration and invasion were evaluated by wound healing assay and transwell assay. Western blot analysis was carried out to assess the underlying molecular mechanisms. Tumor formation and metastasis were determined by in vivo mouse experiments.

RESULTS

KIF26B levels were significantly increased in breast cancer cells and patient samples. KIF26B level correlated with tumor size, TNM grade, and differentiation in patients with breast cancer. Overexpressing KIF26B in vitro promoted breast cancer cell proliferation and migration by activating FGF2/ERK signaling, while silencing KIF26B had the opposite effects. Similarly, KIF26B knockdown repressed tumor formation and metastasis in nude mice.

CONCLUSION

KIF26B promoted the development and progression of breast cancer and might act as a potential therapeutic target for treating breast cancer.

Expression of vasohibin-1 and -2 predicts poor prognosis among patients with squamous cell carcinoma of the esophagus

Vasohibin (VASH) -1 and -2 are novel angiogenic regulators. The aim of the present study was to assess the prognostic values of VASH1 expression and VASH2 expression in esophageal squamous cell carcinoma (ESCC). A total of 209 patients with ESCC were investigated. Resected tumor specimens were immunostained using anti-CD34 antibody, anti-VASH1 antibody and anti-VASH2 antibody. The ratio of the microvessels density and the VASH1 density as the VASH1-positive ratio were defined and the patients were divided into two groups (a high VASH1 group and a low VASH1 group) according to the average value. The patients were also divided into two groups (a high VASH2 group and a low VASH2 group) according to VASH2 expression upon immunostaining. The clinical outcomes of these two groups were then evaluated. The high VASH1 group contained 106 patients (50.7%). The high VASH2 group contained 48 patients (23.0%). Long-term survival was significantly poorer in the high VASH1 group compared with that in the low VASH1 group. A slight correlation between VASH1 expression and VASH2 expression was observed. The low VASH1/low VASH2 group had a better prognosis than the other three groups with different combinations of VASH1 and VASH2 expression levels. The present study showed that high VASH1 expression and high VASH2 expression may be novel independent predictors of a poor prognosis in patients with ESCC and that a slight correlation between VASH1 and VASH2 expression existed. The present findings suggest that combined evaluation of VASH1 and VASH2 expression should provide an improved understanding of their clinicopathological features.

The roles of vasohibin and its family members: Beyond angiogenesis modulators

Vasohibin-1 is an intrinsic angiogenesis inhibitor, and is expressed in endothelial cells via induction by pro-angiogenesis factors. It is known to inhibit several processes of angiogenesis, with different mechanisms from extrinsic angiogenesis inhibitors. Vasohibin-2 is mainly expressed by mononuclear cells which have been mobilized from bone marrow. It not only promotes angiogenesis, but also modulates the releases of FGF-2 and VEGF, which are the two major inducers for vasohibin1. Hypoxic environment induces the expression of hypoxia-inducible Factor 1α with a result of VEGF release nearly in all tumor cell lines and tissues. However, it has been observed that hypoxia reduces the inducible effects of VEGF on vasohibin, which indicates that a complicated mechanism exists in the angiogenesis. Vasohibin and its family members play important roles in both the physiological and pathological procedures, in contrary but complementary patterns. Furthermore, human aortic smooth muscle cells and fibroblast have also been detected to express vasohibin on a moderate to weak scale range. Recently, the results of an increasing number of studies in vivo have shown that vasohibin can also be detected in several cancers, and is associated with micro-vessel densities, histology grades, invasions, poor clinical features, metastasis, and dissemination in abdominal cavities, as well as EMT. In more recent reports, it has been confirmed that, along with being angiogenesis regulators, a variety of other roles have been associated with this family. The focus of this study was the upstream regulatory mechanisms of vasohibin expressions, and their role in regard to the downstream target proteins of vasohibin, especially in carcinoma. Vasohibin is considered to be an original angiogenesis inhibitor, and has a much broader significance in pathological processes. It can be taken as an independent prognostic factor, as well as a potential strategy for cancer therapy programs.