Vasohibin 2 is transcriptionally activated and promotes angiogenesis in hepatocellular carcinoma

Identification of VEGFs-related gene signature for predicting microangiogenesis and hepatocellular carcinoma prognosis

Microangiogenesis is an important prognostic factor in various cancers, including hepatocellular carcinoma (HCC). The Vascular Endothelial Growth Factor (VEGF) has been shown to contribute to tumor angiogenesis. Recently, several studies have investigated the regulation of VEGF production by a single gene, with few researchers exploring all genes that affect VEGF production. In this study, we comprehensively analyzed all genes affecting VEGF production in HCC and developed a risk model and gene-based risk score based on VEGF production. Moreover, the model's predictive capacity on prognosis of HCCs was verified using training and validation datasets. The developed model showed good prediction of the overall survival rate. Patients with a higher risk score experienced poor outcomes compared to those with a lower risk score. Furthermore, we identified the immunological causes of the poor prognosis of patients with high-risk scores comparing with those with low-risk scores.

High Vasohibin-2 expression correlated with autophagy in proliferative diabetic retinopathy

Vasohibin-2 (VASH2) is confirmed to be associated with angiogenesis. To investigate the vitreous levels of VASH2 and how VASH2 induces angiogenesis in proliferative diabetic retinopathy (PDR), a total of 120 eyes were enrolled in this prospective and randomized controlled study and the vitreous level of VASH2 was quantified by Luminex liquid suspension chip. Vector systems were applied in human retinal microvascular endothelial cells (HRMECs) for VASH2 gene overexpression, along with interfering lentiviral vectors (VASH2-shRNA) for VASH2 gene silencing. Cell migration, autophagic flux, as well as the expression of α-tubulin, detyrosinated ⍺-tubulin, LC3 II/LC3 I, P62 were detected under normal, VASH2 overexpression, or interference conditions. The level of VASH2 in PDR patients was significantly higher (218.61 ± 30.14 pg/ml) than that in ERM/MH patients (80.78 ± 2.05 pg/ml) (P = 0.001). The migration ability of HRMECs was significantly increased in VASH2 overexpression group, while in the interfering group, the migration ability decreased. VASH2 increased the detyrosination of ⍺-tubulin. The high fluorescence intensity of autophagic flux showed an activation of autophagy in VASH2 overexpression group, which was also confirmed by the increase of LC3 II/LC3 I ratio and the decrease of P62. Collectively, the present study shows in PDR, vitreous level of VASH2 is higher. VASH2 promotes neovascularization by inducing autophagy, suggesting VASH2 could be a new anti-angiogenic drug target for PDR.

Development of a Novel and Simple Anti-Metastatic Cancer Treatment Targeting Vasohibin-2

Vasohibin-2 (VASH2), a homologue of vasohibin-1 (VASH1), is overexpressed in various cancer cells and promotes tumor progression. We therefore regard VASH2 as a molecular target for cancer treatment. Here we applied vaccine technology to develop a therapy against VASH2. We selected two amino acid sequences of VASH2 protein; the MTG and RRR peptides, which contain possible B cell epitopes. These sequences are identical between the human and murine VASH2 proteins and distinct from those of the VASH1 protein. We conjugated these peptides with the carrier protein keyhole limpet hemocyanin, mixed with an adjuvant, and injected subcutaneously twice at a 2-week interval in mice. Both vaccines increased antibodies against the antigen peptide; however, only the MTG peptide vaccine increased antibodies that recognized the recombinant VASH2 protein. When Lewis lung cancer (LLC) cells were subcutaneously inoculated, tumors isolated from mice immunized with the MTG peptide vaccine showed a significant decrease in the expression of epithelial-to-mesenchymal transition (EMT) markers. EMT is responsible for cancer cell invasion and metastasis. When the LLC cells were injected into the tail vein, the MTG peptide vaccine inhibited lung metastasis. Moreover, the MTG peptide vaccine inhibited the metastasis of pancreatic cancer cells to the liver in an orthotopic mouse model, and there was a significant inverse correlation between the ELISA titer and metastasis inhibition. Therefore, we propose that the MTG peptide vaccine is a novel anti-metastatic cancer treatment that targets VASH2 and can be applied even in the most malignant and highly metastatic pancreatic cancer.

Novel strategy of liver cancer treatment with modified antisense oligonucleotides targeting human vasohibin-2

Vasohihibin-2 (VASH2) is a homolog of vasohibin-1 (VASH1) and is overexpressed in various cancers. Vasohihibin-2 acts on both cancer cells and cancer microenvironmental cells. Previous analyses have shown that VASH2 promotes cancer progression and abrogation of VASH2 results in significant anticancer effects. We therefore propose VASH2 to be a practical molecular target for cancer treatment. Modifications of antisense oligonucleotide (ASO) such as bridged nucleic acids (BNA)-based modification increases the specificity and stability of ASO, and are now applied to the development of a number of oligonucleotide-based drugs. Here we designed human VASH2-ASOs, selected an optimal one, and developed 2',4'-BNA-based VASH2-ASO. When systemically administered, naked 2',4'-BNA-based VASH2-ASO accumulated in the liver and showed its gene-silencing activity. We then examined the effect of 2',4'-BNA-based VASH2-ASO in liver cancers. Intraperitoneal injection of naked 2',4'-BNA-based VASH2-ASO exerted a potent antitumor effect on orthotopically inoculated human hepatocellular carcinoma cells. The same manipulation also showed potent antitumor activity on the splenic inoculation of human colon cancer cells for liver metastasis. These results provide a novel strategy for the treatment of primary as well as metastatic liver cancers by using modified ASOs targeting VASH2.

Insulin-like growth factor-2 mRNA-binding protein 3 promotes cell migration, invasion, and epithelial-mesenchymal transition of esophageal squamous cell carcinoma cells by targeting zinc finger E-box-binding homeobox 1 mRNA

The role and mechanism of insulin-like growth factor-2 mRNA-binding protein 3 (IGF2BP3) in the metastasis of esophageal squamous cell carcinoma (ESCC) remain unclear. In this study, IGF2BP3 mRNA and protein expression levels were evaluated in ESCC tissues. Small interfering RNAs (siRNAs), plasmid overexpression, and stable lentivirus transfection were used to manipulate intracellular IGF2BP3 expression levels. The role of IGF2BP3 in ESCC tumorigenesis was investigated in vitro and in vivo. IGF2BP3 target transcripts were detected, and the acetylation effect ratios of the IGF2BP3 promoter region by H3K27ac were determined. IGF2BP3 mRNA expression levels were significantly higher in ESCC tissues than in normal esophageal tissues. Increased IGF2BP3 expression levels were detected in node-negative ESCC tissues and correlated with greater lesion depth in ESCC. Overexpression of IGF2BP3 promoted ESCC development in vitro and in vivo, and IGF2BP3 knockdown caused an opposite effect. IGF2BP3 was found to directly bind to the zinc finger E-box-binding homeobox 1 (Zeb1) mRNA, and the downregulation of IGF2BP3 reduced the stability of Zeb1 mRNA. IGF2BP3 induced epithelial-mesenchymal transition in ESCC cells in a Zeb1-dependent manner. IGF2BP3 was transcriptionally activated in ESCC cell lines via H3K27 acetylation. Our results demonstrate that IGF2BP3 plays a vital role in ESCC cell proliferation, invasion, and metastasis and is a potential therapeutic target for treating ESCC.

Preoperative prediction model for macrotrabecular-massive hepatocellular carcinoma based on contrast-enhanced CT and clinical characteristics: a retrospective study

Objective

To investigate the predictive value of contrast-enhanced computed tomography (CECT) imaging features and clinical factors in identifying the macrotrabecular-massive (MTM) subtype of hepatocellular carcinoma (HCC) preoperatively.

Methods

This retrospective study included 101 consecutive patients with pathology-proven HCC (35 MTM subtype vs. 66 non-MTM subtype) who underwent liver surgery and preoperative CECT scans from January 2017 to November 2021. The imaging features were evaluated by two board-certified abdominal radiologists independently. The clinical characteristics and imaging findings were compared between the MTM and non-MTM subtypes. Univariate and multivariate logistic regression analyses were performed to investigate the association of clinical-radiological variables and MTM-HCCs and develop a predictive model. Subgroup analysis was also performed in BCLC 0-A stage patients. Receiver operating characteristic (ROC) curves analysis was used to determine the optimal cutoff values and the area under the curve (AUC) was employed to evaluate predictive performance.

Results

Intratumor hypoenhancement (odds ratio [OR] = 2.724; 95% confidence interval [CI]: 1.033, 7.467; p = .045), tumors without enhancing capsules (OR = 3.274; 95% CI: 1.209, 9.755; p = .03), high serum alpha-fetoprotein (AFP) (≥ 228 ng/mL, OR = 4.101; 95% CI: 1.523, 11.722; p = .006) and high hemoglobin (≥ 130.5 g/L; OR = 3.943; 95% CI: 1.466, 11.710; p = .009) were independent predictors for MTM-HCCs. The clinical-radiologic (CR) model showed the best predictive performance, achieving an AUC of 0.793, sensitivity of 62.9% and specificity of 81.8%. The CR model also effectively identify MTM-HCCs in early-stage (BCLC 0-A stage) patients.

Conclusion

Combining CECT imaging features and clinical characteristics is an effective method for preoperatively identifying MTM-HCCs, even in early-stage patients. The CR model has high predictive performance and could potentially help guide decision-making regarding aggressive therapies in MTM-HCC patients.

Pathogenesis and Current Treatment Strategies of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most frequent liver cancer with high lethality and low five-year survival rates leading to a substantial worldwide burden for healthcare systems. HCC initiation and progression are favored by different etiological risk factors including hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, non-/and alcoholic fatty liver disease (N/AFLD), and tobacco smoking. In molecular pathogenesis, endogenous alteration in genetics (TP53, TERT, CTNNB1, etc.), epigenetics (DNA-methylation, miRNA, lncRNA, etc.), and dysregulation of key signaling pathways (Wnt/β-catenin, JAK/STAT, etc.) strongly contribute to the development of HCC. The multitude and complexity of different pathomechanisms also reflect the difficulties in tailored medical therapy of HCC. Treatment options for HCC are strictly dependent on tumor staging and liver function, which are structured by the updated Barcelona Clinic Liver Cancer classification system. Surgical resection, local ablative techniques, and liver transplantation are valid and curative therapeutic options for early tumor stages. For multifocal and metastatic diseases, systemic therapy is recommended. While Sorafenib had been the standalone HCC first-line therapy for decades, recent developments had led to the approval of new treatment options as first-line as well as second-line treatment. Anti-PD-L1 directed combination therapies either with anti-VEGF directed agents or with anti-CTLA-4 active substances have been implemented as the new treatment standard in the first-line setting. However, data from clinical trials indicate different responses on specific therapeutic regimens depending on the underlying pathogenesis of hepatocellular cancer. Therefore, histopathological examinations have been re-emphasized by current international clinical guidelines in addition to the standardized radiological diagnosis using contrast-enhanced cross-sectional imaging. In this review, we emphasize the current knowledge on molecular pathogenesis of hepatocellular carcinoma. On this occasion, the treatment sequences for early and advanced tumor stages according to the recently updated Barcelona Clinic Liver Cancer classification system and the current algorithm of systemic therapy (first-, second-, and third-line treatment) are summarized. Furthermore, we discuss novel precautional and pre-therapeutic approaches including therapeutic vaccination, adoptive cell transfer, locoregional therapy enhancement, and non-coding RNA-based therapy as promising treatment options. These novel treatments may prolong overall survival rates in regard with quality of life and liver function as mainstay of HCC therapy.

Silencing TUBB3 Expression Destroys the Tegument and Flame Cells of Echinococcus multilocularis Protoscoleces

Alveolar echinococcosis (AE), caused by infection with the larvae of Echinococcus multilocularis, is a neglected tropical disease and zoonosis that causes remarkable morbidity in humans and has economic importance in the livestock industry worldwide. The growth of this parasite resembles the invasion and proliferation of malignant tumours. Microtubules, especially the β-tubulin subunit in the exposed end, are the targets of many antitumour drugs. However, the role of TUBB3, which is the most studied isotype in solid tumours and is also a marker of biological aggressiveness associated with the modulation of tumour metastatic abilities in the growth and development of platyhelminths, is unknown. In this study, protoscoleces (PSCs) are cultivated in monophasic medium in vitro. Using electroporated short interfering RNA (siRNA), EmTUBB3 knockdown was performed with two EmTUBB3-specific siRNAs (siRNA-1 and siRNA-2). qRT–PCR was performed to detect the expression of TUBB3. PSCs viability and the evagination rate and number of body contractions were quantified under a light microscope. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to observe the ultra-morphological changes of the parasites. After siRNA interference, the EmTUBB3 expression in E. multilocularis PSCs was significantly reduced. Reduced viability, a decreased evagination rate and a decreased number of body contractions were also documented. In particular, shrinkage and roughness of the tegument were observed. Ultrastructural changes included marked damage to flame cells, cracked cilia structures enclosed in the cell body and ruptured microtubule structures. EmTUBB3 possibly plays a crucial role in tegument and flame cell integrity in E. multilocularis PSCs. Novel drugs targeting this specific beta-tubulin isotype in E. multilocularis are potential methods for disease control and deserve further attention.

Roles and regulation of histone acetylation in hepatocellular carcinoma

Hepatocellular Carcinoma (HCC) is the most frequent malignant tumor of the liver, but its prognosis is poor. Histone acetylation is an important epigenetic regulatory mode that modulates chromatin structure and transcriptional status to control gene expression in eukaryotic cells. Generally, histone acetylation and deacetylation processes are controlled by the opposing activities of histone acetyltransferases (HATs) and histone deacetylases (HDACs). Dysregulation of histone modification is reported to drive aberrant transcriptional programmes that facilitate liver cancer onset and progression. Emerging studies have demonstrated that several HDAC inhibitors exert tumor-suppressive properties via activation of various cell death molecular pathways in HCC. However, the complexity involved in the epigenetic transcription modifications and non-epigenetic cellular signaling processes limit their potential clinical applications. This review brings an in-depth view of the oncogenic mechanisms reported to be related to aberrant HCC-associated histone acetylation, which might provide new insights into the effective therapeutic strategies to prevent and treat HCC.

Vasohibin-1 and -2 in pulmonary lymphangioleiomyomatosis (LAM) cells associated with angiogenic and prognostic factors

Lymphangioleiomyomatosis (LAM) is a rare pulmonary neoplasm, clinically associated with dyspnea and respiratory failure. Current therapeutic modalities do not necessarily reach satisfactory outcome and novel therapeutic approaches are currently warranted. Therefore, in this study, we focused on vasohibin-1 (VASH1) and -2 (VASH2); VASH1 terminated and VASH2 promoted angiogenesis. In addition, both VASH1/2 were reported to influence the progression of various human malignancies. We first performed hierarchical clustering analysis to attempt to classify 36 LAM cases into three different clusters according to immunoreactivity of VASH1/2 and other angiogenic and prognostic factors of LAM; VEGFR1/2/3, p-mTOR, p-S6, p-4EBP, ERα, PgR, MMP2, and MMP9. The cluster harboring higher angiogenic factors had higher VASH1/2 status. VASH1 was significantly positively correlated with VEGFR2, MMP9, and p-mTOR (p-value <0.05), and VASH2 with both angiogenic and prognostic factors including VEGFR1, PgR, MMP9, p-mTOR, p-S6, and p-4EBP (p-value <0.05). Subsequent PCR array of angiogenic genes demonstrated that high VASH1 mRNA was significantly positively associated with the status of SPHK1 and TYPM, lower EGF and EFNB2 (p-value <0.05), and high VASH2 mRNA negatively with MMP2 (p-value <0.05). VASH1 was considered to be up-regulated by activation of angiogenesis, whereas VASH2 could influence the angiogenesis and progression of LAM.

Circular RNA hsa_circ_0001306 Functions as a Competing Endogenous RNA to Regulate FBXW7 Expression by Sponging miR-527 in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common types of cancer worldwide. Circular RNAs (circRNAs) have been reported to regulate many types of cancers, including HCC. The purpose of this study was to investigate the potential roles of hsa_circ_0001306 in HCC. Firstly, the downregulation of hsa_circ_0001306 was identified by high‑throughput RNA sequencing and further verified by qRT-PCR. Secondly, we evaluated the effects of hsa_circ_0001306 on HCC cell proliferation, invasion, cell cycle. Finally, we used an animal model to validate the in vitro experimental results. The expression of hsa_circ_0001306 was closely related to tumor size. Knockdown of hsa_circ_0001306 could downregulate F-box and WD repeat domain containing 7(FBXW7), a target of miR-527, thereby promoting HCC cell proliferation and invasion. Furthermore, hsa_circ_0001306 siRNA increased the multiplication rate of HCC tumors. Mechanistic studies indicated that hsa_circ_0001306 acts as a ceRNA for miR-527, which resulted in the reduction of its endogenous target, FBXW7. Hsa_circ_001306 is significantly downregulated in HCC, and the hsa_circ_0001306/miR-527/FBXW7 axis plays an important role in HCC progression.

Epigenetic Mechanisms Involved in HCV-Induced Hepatocellular Carcinoma (HCC)

Hepatocellular carcinoma (HCC), is the third leading cause of cancer-related deaths, which is largely caused by virus infection. About 80% of the virus-infected people develop a chronic infection that eventually leads to liver cirrhosis and hepatocellular carcinoma (HCC). With approximately 71 million HCV chronic infected patients worldwide, they still have a high risk of HCC in the near future. However, the mechanisms of carcinogenesis in chronic HCV infection have not been still fully understood, which involve a complex epigenetic regulation and cellular signaling pathways. Here, we summarize 18 specific gene targets and different signaling pathways involved in recent findings. With these epigenetic alterations requiring histone modifications and DNA hyper or hypo-methylation of these specific genes, the dysregulation of gene expression is also associated with different signaling pathways for the HCV life cycle and HCC. These findings provide a novel insight into a correlation between HCV infection and HCC tumorigenesis, as well as potentially preventable approaches. Hepatitis C virus (HCV) infection largely causes hepatocellular carcinoma (HCC) worldwide with 3 to 4 million newly infected cases diagnosed each year. It is urgent to explore its underlying molecular mechanisms for therapeutic treatment and biomarker discovery. However, the mechanisms of carcinogenesis in chronic HCV infection have not been still fully understood, which involve a complex epigenetic regulation and cellular signaling pathways. Here, we summarize 18 specific gene targets and different signaling pathways involved in recent findings. With these epigenetic alterations requiring histone modifications and DNA hyper or hypo-methylation of these specific genes, the dysregulation of gene expression is also associated with different signaling pathways for the HCV life cycle and HCC. These findings provide a novel insight into a correlation between HCV infection and HCC tumorigenesis, as well as potentially preventable approaches.

Vasohibin-2 Aggravates Development of Ascending Aortic Aneurysms but not Abdominal Aortic Aneurysms nor Atherosclerosis in ApoE-Deficient Mice

BACKGROUND

Vasohibin-2 (VASH2) has been isolated as a homologue of vasohibin-1 (VASH1) that promotes angiogenesis counteracting with VASH1. Chronic angiotensin II (AngII) infusion promotes both ascending and abdominal aortic aneurysms (AAs) in mice. The present study aimed to investigate whether exogenous VASH2 influenced AngII-induced vascular pathology in apolipoprotein E-deficient (ApoE-/-) mice.

METHODS

Male, ApoE-/- mice (9-14 weeks old) were injected with Ad LacZ or Ad VASH2. After a week, saline or AngII (1,000 ng/kg/minute) was infused into the mice subcutaneously via mini-osmotic pumps for 3 weeks. Consequently, all these mice were divided into 4 groups: saline + LacZ (n = 5), saline + VASH2 (n = 5), AngII + LacZ (n = 18), and AngII + VASH2 (n = 17).

RESULTS

Exogenous VASH2 had no significant effect on ex vivo maximal diameters of abdominal aortas (AngII + LacZ: 1.67 ± 0.17 mm, AngII + VASH2: 1.52 ± 0.16 mm, n.s.) or elastin fragmentation and accumulation of inflammatory cells. Conversely, exogenous VASH2 significantly increased intima areas of aortic arches (AngII + LacZ: 16.6 ± 0.27 mm2, AngII + VASH2: 18.6 ± 0.64 mm2, P = 0.006). VASH2 effect of AngII-induced ascending AAs was associated with increased cleaved caspase-3 abundance. AngII-induced atherosclerosis was not altered by VASH2.

CONCLUSIONS

The present study demonstrated that augmented VASH2 expression had no effect of AngII-induced abdominal AAs or atherosclerosis, while increasing dilation in the ascending aorta.

Activation of the clock gene TIMELESS by H3k27 acetylation promotes colorectal cancer tumorigenesis by binding to Myosin-9

BACKGROUND

Colorectal cancer (CRC) is a common tumor characterized by its high mortality. However, the underlying molecular mechanisms that drive CRC tumorigenesis are unclear. Clock genes have important roles in tumor development. In the present study, the expression and functions of clock gene TIMELESS (encoding the Timeless protein) in CRC were investigated.

METHODS

Immunohistochemistry, cell proliferation, migration, invasion, EMT and xenograft tumor experiments were used to prove the function of Timeless in the tumorigenesis of CRC. Immunoprecipitation, mass spectrometry, Immunofluorescence and Chromatin immunoprecipitation (ChIP) were utilized to clarify the mechanism of Timeless in regulating CRC tumorigenesis.

RESULTS

We found that Timeless was upregulated in CRC tissues compared with corresponding normal tissues and its expression was closely associated with the TNM stages and overall survival of CRC patients. Functional studies demonstrated that Timeless promoted the proliferation, invasion, and EMT of CRC cells in vitro and in vivo. Mechanistic investigations showed that Timeless activated the β-catenin signal pathway by binding to Myosin-9, which binds to β-catenin to induce its nuclear translocation. The upregulation of Timeless was attributed to CREB-binding protein (CBP)/p300-mediated H3K27 acetylation of the promoter region of Timeless.

CONCLUSION

Timeless regulates the tumorigenesis of CRC by binding to and regulating myosin-9, suggesting Timeless might be a potential prognostic biomarker and therapeutic target for CRC.

An expanded mouse testis transcriptome and mass spectrometry defines novel proteins

The testis transcriptome is exceptionally complex. Despite its complexity, previous testis transcriptome analyses relied on a reductive method for transcript identification, thus underestimating transcriptome complexity. We describe here a more complete testis transcriptome generated by combining Tuxedo, a reductive method, and spliced-RUM, a combinatorial transcript-building approach. Forty-two percent of the expanded testis transcriptome is composed of unannotated RNAs with novel isoforms of known genes and novel genes constituting 78 and 9.8% of the newly discovered transcripts, respectively. Across tissues, novel transcripts were predominantly expressed in the testis with the exception of novel isoforms which were also highly expressed in the adult ovary. Within the testis, novel isoform expression was distributed equally across all cell types while novel genes were predominantly expressed in meiotic and post-meiotic germ cells. The majority of novel isoforms retained their protein-coding potential while most novel genes had low protein-coding potential. However, a subset of novel genes had protein-coding potentials equivalent to known protein-coding genes. Shotgun mass spectrometry of round spermatid total protein identified unique peptides from four novel genes along with seven annotated non-coding RNAs. These analyses demonstrate the testis expresses a wide range of novel transcripts that give rise to novel proteins.

The Tubulin Code in Mitosis and Cancer

The “tubulin code” combines different α/β-tubulin isotypes with several post-translational modifications (PTMs) to generate microtubule diversity in cells. During cell division, specific microtubule populations in the mitotic spindle are differentially modified, but only recently, the functional significance of the tubulin code, with particular emphasis on the role specified by tubulin PTMs, started to be elucidated. This is the case of α-tubulin detyrosination, which was shown to guide chromosomes during congression to the metaphase plate and allow the discrimination of mitotic errors, whose correction is required to prevent chromosomal instability—a hallmark of human cancers implicated in tumor evolution and metastasis. Although alterations in the expression of certain tubulin isotypes and associated PTMs have been reported in human cancers, it remains unclear whether and how the tubulin code has any functional implications for cancer cell properties. Here, we review the role of the tubulin code in chromosome segregation during mitosis and how it impacts cancer cell properties. In this context, we discuss the existence of an emerging “cancer tubulin code” and the respective implications for diagnostic, prognostic and therapeutic purposes.

Roles of lncRNAs in cancer: Focusing on angiogenesis

Approximately 98% of the human genome consists of non-coding sequences that are classified into two classes by size: small non-coding RNAs (≤200 nucleotides) and long non-coding RNAs (≥200 nucleotides). Long non-coding RNAs (lncRNAs) are involved in various cellular events and act as guides, signals, decoys, and dynamic scaffolds. Due to their oncogenic and tumor suppressive roles, lncRNAs are important in cancer development and growth. LncRNAs play their roles by modulating cancer hallmarks, including DNA damage, metastasis, immune escape, cell stemness, drug resistance, metabolic reprogramming, and angiogenesis. Angiogenesis is vital for solid tumors which guarantees their growth beyond 2 mm³. Tumor angiogenesis is a complex process and is regulated through interaction between pro-angiogenic and anti-angiogenic factors within the tumor microenvironment. There are accumulating evidence that different lncRNAs regulate tumor angiogenesis. In this paper, we described the functions and mechanisms of lncRNAs in tumor angiogenesis.

Epigenetic regulation of histone H3 in the process of hepatocellular tumorigenesis

Better understanding of epigenetic regulation of hepatocellular carcinoma (HCC) will help us to cure this most common malignant liver cancer worldwide. The underlying mechanisms of HCC tumorigenesis are genomic aberrations regulated by genetic and epigenetic modifications. Histone H3 lysine modifications regulate histone structure and modulate transcriptional factor binding with target gene promoters. Targetting genes include VASH2, fatty acids synthase, RIZ1, FBP1, MPP1/3, YAP, which affect tumorigenesis, metabolisms, angiogenesis, and metastasis. Signal pathway studies demonstrate that the HGF-MET-MLL axis, phosphatase and tensin homolog (PTEN)-PI3K-Akt axis; WNT-β-catenin signal pathway is involved in histone H3 modification. A variety of factors such as virus infection, reactive oxygen species, food-borne toxins, irradiation, or non-coding RNA cause hepatocellular DNA damage or modification. Dysfunctional DNA repair mechanisms, including those at the epigenetic level are also major causes of HCC tumorigenesis. The development of therapies based on epigenetic regulatory mechanisms has great potential to advance the care of HCC patients in the future.

Vasohibin-2 plays an essential role in metastasis of pancreatic ductal adenocarcinoma

Vasohibin-2 (VASH2) is expressed in various cancers and promotes their progression. We recently reported that pancreatic cancer patients with higher VASH2 expression show poorer prognosis. Herein, we sought to characterize the role of VASH2 in pancreatic cancer. We used LSL-Kras^G12D ; LSL-Trp53^R172H ; Pdx-1-Cre (KPC) mice, a mouse model of pancreatic ductal adenocarcinoma (PDAC), and cells isolated from them (KPC cells). Knockdown of Vash2 from PDAC cells did not affect their proliferation, but decreased their migration. When Vash2-knockdown PDAC cells were orthotopically inoculated, liver metastasis and peritoneal dissemination were reduced, and the survival period was significantly prolonged. When KPC mice were crossed with Vash2-deficient mice, metastasis was significantly decreased in Vash2-deficient KPC mice. VASH2 was recently identified to have tubulin carboxypeptidase activity. VASH2 knockdown decreased, whereas VASH2 overexpression increased tubulin detyrosination of PDAC cells, and tubulin carboxypeptidase (TCP) inhibitor parthenolide inhibited VASH2-induced cell migration. We next clarified its role in the tumor microenvironment. Tumor angiogenesis was significantly abrogated in vivo when VASH2 was knocked down or deleted. We further examined genes downregulated by Vash2 knockdown in KPC cells, and found chemokines and cytokines that were responsible for the recruitment of myeloid derived suppressor cells (MDSC). Indeed, MDSC were accumulated in PDAC of KPC mice, and they were significantly decreased in Vash2-deficient KPC mice. These findings suggest that VASH2 plays an essential role in the metastasis of PDAC with multiple effects on both cancer cells and the tumor microenvironment, including tubulin detyrosination, tumor angiogenesis and evasion of tumor immunity.

VASH2 Promotes Cell Proliferation and Resistance to Doxorubicin in Non-Small Cell Lung Cancer via AKT Signaling

Vasohibin2 (VASH2), a proangiogenic factor, has been demonstrated to play an oncogenic role in some common human cancers. However, the detailed function of VASH2 in non-small cell lung cancer (NSCLC) has not previously been studied. In this study, we found that VASH2 was significantly upregulated in NSCLC tissues and cell lines, and its increased expression was associated with NSCLC progression and poor prognosis of patients. Knockdown of VASH2 markedly inhibited cell proliferation and P-glycoprotein expression in NSCLC cells. Overexpression of VASH2 enhanced cell proliferation, P-glycoprotein expression, as well as doxorubicin resistance in NSCLC cells. Moreover, the expression levels of VASH2 were significantly increased in newly established doxorubicin-resistant NSCLC cells. Molecular mechanism investigation revealed that inhibition of VASH2 expression in NSCLC cells suppressed the activity of AKT signaling, and overexpression of VASH2 enhanced the activity of AKT signaling. We further showed that downregulation of AKT signaling activity using AKT inhibitor LY294002 markedly inhibited NSCLC cell proliferation and resistance to doxorubicin induced by VASH2. In conclusion, the findings in the present study indicate that VASH2 promotes NSCLC cell proliferation and resistance to doxorubicin via modulation of AKT signaling. Thus, we suggest that VASH2 may become a potential therapeutic target for the treatment of NSCLC.

BjussuLAAO-II induces cytotoxicity and alters DNA methylation of cell-cycle genes in monocultured/co-cultured HepG2 cells

Background:

The use of animal venoms and their toxins as material sources for biotechnological applications has received much attention from the pharmaceutical industry. L-amino acid oxidases from snake venoms (SV-LAAOs) have demonstrated innumerous biological effects and pharmacological potential against different cancer types. Hepatocellular carcinoma has increased worldwide, and the aberrant DNA methylation of liver cells is a common mechanism to promote hepatic tumorigenesis. Moreover, tumor microenvironment plays a major role in neoplastic transformation. To elucidate the molecular mechanisms responsible for the cytotoxic effects of SV-LAAO in human cancer cells, this study aimed to evaluate the cytotoxicity and the alterations in DNA methylation profiler in the promoter regions of cell-cycle genes induced by BjussuLAAO-II, an LAAO from Bothrops jaracussu venom, in human hepatocellular carcinoma (HepG2) cells in monoculture and co-culture with endothelial (HUVEC) cells.

Methods:

BjussuLAAO-II concentrations were 0.25, 0.50, 1.00 and 5.00 μg/mL. Cell viability was assessed by MTT assay and DNA methylation of the promoter regions of 22 cell-cycle genes by EpiTect Methyl II PCR array.

Results:

BjussuLAAO-II decreased the cell viability of HepG2 cells in monoculture at all concentrations tested. In co-culture, 1.00 and 5.00 μg/mL induced cytotoxicity (p < 0.05). BjussuLAAO-II increased the methylation of CCND1 and decreased the methylation of CDKN1A in monoculture and GADD45A in both cell-culture models (p < 0.05).

Conclusion:

Data showed BjussuLAAO-II induced cytotoxicity and altered DNA methylation of the promoter regions of cell-cycle genes in HepG2 cells in monoculture and co-culture models. We suggested the analysis of DNA methylation profile of GADD45A as a potential biomarker of the cell cycle effects of BjussuLAAO-II in cancer cells. The tumor microenvironment should be considered to comprise part of biotechnological strategies during the development of snake-toxin-based novel drugs.

Non-Coding RNAs in Glioma

Glioma is the most aggressive brain tumor of the central nervous system. The ability of glioma cells to migrate, rapidly diffuse and invade normal adjacent tissue, their sustained proliferation, and heterogeneity contribute to an overall survival of approximately 15 months for most patients with high grade glioma. Numerous studies indicate that non-coding RNA species have critical functions across biological processes that regulate glioma initiation and progression. Recently, new data emerged, which shows that the cross-regulation between long non-coding RNAs and small non-coding RNAs contribute to phenotypic diversity of glioblastoma subclasses. In this paper, we review data of long non-coding RNA expression, which was evaluated in human glioma tissue samples during a five-year period. Thus, this review summarizes the following: (I) the role of non-coding RNAs in glioblastoma pathogenesis, (II) the potential application of non-coding RNA species in glioma-grading, (III) crosstalk between lncRNAs and miRNAs (IV) future perspectives of non-coding RNAs as biomarkers for glioma.

Gene expression profiling of spontaneously occurring canine mammary tumours: Insight into gene networks and pathways linked to cancer pathogenesis

Spontaneously occurring canine mammary tumours (CMTs) are the most common neoplasms of unspayed female dogs leading to thrice higher mortality rates than human breast cancer. These are also attractive models for human breast cancer studies owing to clinical and molecular similarities. Thus, they are important candidates for biomarker studies and understanding cancer pathobiology. The study was designed to explore underlying molecular networks and pathways in CMTs for deciphering new prognostic factors and therapeutic targets. To gain an insight into various pathways and networks associated with the development and pathogenesis of CMTs, comparative cDNA microarray expression profiling was performed using CMT tissues and healthy mammary gland tissues. Upon analysis, 1700 and 1287 differentially expressed genes (DEGs, P ≤ 0.05) were identified in malignant and benign tissues, respectively. DEGs identified from microarray analysis were further annotated using the Ingenuity Systems Pathway Analysis (IPA) tool for detection of deregulated canonical pathways, upstream regulators, and networks associated with malignant, as well as, benign disease. Top scoring key networks in benign and malignant mammary tumours were having central nodes of VEGF and BUB1B, respectively. Cyclins & cell cycle regulation and TREM1 signalling were amongst the top activated canonical pathways in CMTs. Other cancer related significant pathways like apoptosis signalling, dendritic cell maturation, DNA recombination and repair, Wnt/β-catenin signalling, etc. were also found to be altered. Furthermore, seven proteins (ANXA2, APOCII, CDK6, GATC, GDI2, GNAQ and MYH9) highly up-regulated in malignant tissues were identified by two-dimensional gel electrophoresis (2DE) and MALDI-TOF PMF studies which were in concordance with microarray data. Thus, the study has uncovered ample number of candidate genes associated with CMTs which need to be further validated as therapeutic targets and prognostic markers.

Endoplasmic reticulum resident oxidase ERO1-Lalpha promotes hepatocellular carcinoma metastasis and angiogenesis through the S1PR1/STAT3/VEGF-A pathway

Mounting evidence demonstrates that expression of ERO1α, an endoplasmic reticulum (ER)-resident oxidase, is a poor prognosis factor in a variety of human cancers. However, the clinical relevance of ERO1α and its molecular mechanisms underlying tumor progression have not been determined for hepatocellular carcinoma (HCC). ERO1α expression levels in HCC tissues and cells were detected by quantitative real-time PCR and western blotting. ERO1α shRNAs and overexpression vector were transfected into HCC cells to downregulate or upregulate ERO1α expression. In vitro and in vivo assays were performed to investigate the function of ERO1α in invasion, metastasis, and angiogenesis of HCC. We found high ERO1α expression in HCC tissues and cells that was significantly associated with metastasis and poor clinicopathologic features of vascular invasion, advanced Edmondson Grade, and TNM stage. Loss-of-function and gain-of-function studies showed that ERO1α prompted migration, invasion, epithelial–mesenchymal transition (EMT), and angiogenesis of HCC cells both in vitro and in vivo. Further studies verified a positive correlation between ERO1α and S1PR1, upregulated in metastatic HCC tissues compared with HCC tissues without metastasis. S1PR1 knockdown markedly diminished the effects of ERO1α on HCC cell migration, invasion and vascular endothelial growth factor (VEGF) expression. Most importantly, ERO1α knockdown significantly repressed the death of HCC xenograft mouse models by reducing tumor distant metastasis, and host angiogenesis by suppressing the expression of S1PR1, p-STAT3, and VEGF-A in HCC cells. Our findings suggest that ERO1α is significantly correlated with reduced survival and poor prognosis, and promotes HCC metastasis and angiogenesis by triggering the S1PR1/STAT3/VEGF-A signaling pathway. ERO1α might be a novel candidate in HCC prognosis and therapy.

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.

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.

Vasohibins encode tubulin detyrosinating activity

Tubulin is subjected to a number of posttranslational modifications to generate heterogeneous microtubules. The modifications include removal and ligation of the C-terminal tyrosine of ⍺-tubulin. The enzymes responsible for detyrosination, an activity first observed 40 years ago, have remained elusive. We applied a genetic screen in haploid human cells to find regulators of tubulin detyrosination. We identified SVBP, a peptide that regulates the abundance of vasohibins (VASH1 and VASH2). Vasohibins, but not SVBP alone, increased detyrosination of ⍺-tubulin, and purified vasohibins removed the C-terminal tyrosine of ⍺-tubulin. We found that vasohibins play a cell type-dependent role in detyrosination, although cells also contain an additional detyrosinating activity. Thus, vasohibins, hitherto studied as secreted angiogenesis regulators, constitute a long-sought missing link in the tubulin tyrosination cycle.

Requisite role of vasohibin-2 in spontaneous gastric cancer formation and accumulation of cancer-associated fibroblasts

The vasohibin (VASH) family consists of two genes, VASH1 and VASH2. VASH1 is mainly expressed in vascular endothelial cells and suppresses angiogenesis in an autocrine manner, whereas VASH2 is mainly expressed in cancer cells and exhibits pro‐angiogenic activity. Employing adenomatous polyposis coli gene mutant mice, we recently reported on the role of Vash2 in the spontaneous formation of intestinal tumors. In this study, we used K19‐Wnt1/C2mE (Gan) mice and examined the role of Vash2 in spontaneous gastric cancer formation. Gan mice spontaneously develop gastric tumors by activation of Wnt and prostaglandin E2 signaling pathways in gastric mucosa after 30 weeks of age. Expression of Vash2 mRNA was significantly increased in gastric tumor tissues compared with normal stomach tissues. When Gan mice were crossed with the Vash2‐deficient (Vash2^LacZ/LacZ) strain, gastric cancer formation was significantly suppressed in Vash2^LacZ/LacZGan mice. Normal composition of gastric mucosa was partially maintained in Vash2^LacZ/LacZGan mice. Knockout of Vash2 caused minimal reduction of tumor angiogenesis but a significant decrease in cancer‐associated fibroblasts (CAF) in tumor stroma. DNA microarray analysis and real‐time RT‐PCR showed that mRNA levels of epiregulin (Ereg) and interleukin‐11 (Il11) were significantly downregulated in gastric tumors of Vash2^LacZ/LacZGan mice. Furthermore, conditioned medium of gastric cancer cells stimulated migration of and α‐smooth muscle actin expression in fibroblasts, whereas conditioned medium of VASH2 knockdown cells attenuated these effects in vitro. These results suggest that VASH2 plays an important role in gastric tumor progression via the accumulation of CAF accompanying upregulation of EREG and IL‐11 expression.

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.

miR-1301 inhibits hepatocellular carcinoma cell migration, invasion, and angiogenesis by decreasing Wnt/β-catenin signaling through targeting BCL9

Metastasis is the major cause of the poor prognosis of hepatocellular carcinoma (HCC), and increasing evidence supports the contribution of miRNAs to cancer progression. However, the exact relationship between the level of miR-1301 expression and HCC cell migration, invasion, and angiogenesis remains largely unknown. Quantitative PCR was used to evaluate the level of miR-1301 expression in HCC tissues and cell lines. Transwell and tube-formation assays were used to measure the effects of miR-1301 on HCC cell migration and invasion, and angiogenesis, respectively. Luciferase reporter assays and western blotting were used to confirm the miR-1301 target genes. We found that miR-1301 was significantly downregulated in HCC tissues and cell lines. Low miR-1301 expression was associated with tumor vascular invasion and Edmondson grade. Gain- and loss-of-function assays demonstrated that miR-1301 inhibited the migration, invasion, epithelial-mesenchymal transition, and angiogenesis of HCC cells in vitro and in vivo. BCL9, upregulated in HCC tissues compared with matched adjacent normal tissues, was inversely correlated to miR-1301 levels in HCC tissues. Through reporter gene and western blot assays, BCL9 was shown to be a direct miR-1301 target. BCL9 overexpression could partially reverse the effects of miR-1301 on HCC cell migration and invasion. Most importantly, miR-1301 overexpression markedly suppressed the death of xenograft mouse models of cancer by reducing tumor load, metastasis, and host angiogenesis by downregulating BCL9, β-catenin, and vascular endothelial growth factor expression in tumor cells. Our observations suggested that miR-1301 inhibits HCC migration, invasion, and angiogenesis via decreasing Wnt/β-catenin signaling through targeting BCL9, and might be a therapeutic target for HCC.

Targeting human vasohibin-2 by a neutralizing monoclonal antibody for anti-cancer treatment

There are two members of the vasohibin (VASH) family, VASH1 and VASH2. VASH1 is expressed mainly in endothelial cells to inhibit angiogenesis, whereas VASH2 is expressed mainly in cancer cells to stimulate tumor growth. The aim of the present study was to establish neutralizing monoclonal antibody (mAb) against human VASH2 and apply it as an anti‐cancer treatment. We previously raised mAb against several synthetic peptides of hVASH1, and found that one of them exhibited neutralizing activity against hVASH1. Because of the similarity in the amino acid sequences between VASH1 and VASH2, we hypothesized that they shared the bioactive center. When we mutated four amino acids within the region, the mutant VASH2 lost its pro‐angiogenic activity. Therefore, we raised mAb against a synthetic peptide overlapping the mutated amino acids of hVASH2, and isolated one clone (1760) that almost completely inhibited the stimulatory effect of hVASH2 on the migration of and tube formation by endothelial cells. When we used this clone 1760 antibody for cancer treatment, the peritoneal injection of it inhibited both tumor growth and angiogenesis in a mouse xenograft model of human cancer cells. In terms of anti‐tumor activity, 25 mg/kg of clone 1760 was equivalent to 5 mg/kg of bevacizmab. From these results, we propose the targeting of human VASH2 with neutralizing mAb as a new strategy for cancer treatment.

Therapeutic implication of 'Iturin A' for targeting MD-2/TLR4 complex to overcome angiogenesis and invasion

Tumor angiogenesis and invasion are deregulated biological processes that drive multistage transformation of tumors from a benign to a life-threatening malignant state activating multiple signaling pathways including MD-2/TLR4/NF-κB. Development of potential inhibitors of this signaling is emerging area for discovery of novel cancer therapeutics. In the current investigation, we identified Iturin A (A lipopeptide molecule from Bacillus megaterium) as a potent inhibitor of angiogenesis and cancer invasion by various in vitro and in vivo methods. Iturin A was found to suppress VEGF, a powerful inducer of angiogenesis and key player in tumor invasion, as confirmed by ELISA, western blot and real time PCR. Iturin A inhibited endothelial tube arrangement, blood capillary formation, endothelial sprouting and vascular growth inside the matrigel. In addition, Iturin A inhibited MMP-2/9 expression in MDA-MB-231 and HUVEC cells. Cancer invasion, migration and colony forming ability were significantly hampered by Iturin A. Expressions of MD-2/TLR4 and its downstream MyD88, IKK-α and NF-κB were also reduced in treated MDA-MB-231 and HUVEC cells. Western blot and immunofluorescence study showed that nuclear accumulation of NF-κB was hampered by Iturin A. MD-2 siRNA or plasmid further confirmed the efficacy of Iturin A by suppressing MD-2/TLR4 signaling pathway. The in silico docking study showed that the Iturin A interacted well with the MD-2 in MD-2/TLR4 receptor complex. Conclusively, inhibition of MD-2/TLR4 complex with Iturin A offered strategic advancement in cancer therapy.

Vasohibin 2 reduces chemosensitivity to gemcitabine in pancreatic cancer cells via Jun proto-oncogene dependent transactivation of ribonucleotide reductase regulatory subunit M2

Background

Vasohibin 2 (VASH2) has previously been identified as an agiogenenic factor and a cancer related protein. Here we investigated the association of VASH2 expression and chemoresistance in pancreatic cancer.

Methods

Immunohistochemical staining for VASH2 was performed on 102 human pancreatic cancer samples. Pancreatic cancer cell line models exhibiting overexpression or knockdown of VASH2 were generated. Gene expression analyses were carried out to determine genes differentially regulated by VASH2. Putative transcription factors that are downstream mediators of gene expression regulated by VASH2 were queried bioinformatically. Dual-luciferase reporter assays and ChIP assays were performed to confirm transactivation of target genes following VASH2 overexpression or knockdown.

Results

VASH2 protein expression was higher in human pancreatic cancer than in paired adjacent tissues and elevated VASH2 levels were associated with gemcitabine chemoresistance. In cell line models of pancreatic cancer, VASH2 expression induced gemcitabine chemoresistance in vitro and in vivo. It was discovered that expression of ribonucleotide reductase regulatory subunit M2 (RRM2) is regulated by VASH2; immunohistochemical analysis demonstrated a positive association of VASH2 expression and RRM2 expression in human pancreatic cancer tissues. Bioinformatics analyses revealed that induction of the Jun proto-oncogene (JUN) by VASH2 is responsible for upregulation of RRM2 expression; this JUN-dependent regulation of RRM2 by VASH2 was confirmed by chromatin immunoprecipitation and dual luciferase reporter assays, which demonstrated that JUN directly binds with the RRM2 promoter to activate transcription.

Conclusions

These data suggest that VASH2 reduces the chemosensitivity to gemcitabine in pancreatic cancer cells via JUN-dependent transactivation of RRM2.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-017-0619-6) contains supplementary material, which is available to authorized users.

Domain architecture of vasohibins required for their chaperone-dependent unconventional extracellular release

Vasohibins (VASH1 and VASH2) are recently identified regulators of angiogenesis and cancer cell functions. They are secreted proteins without any classical secretion signal sequences, and are thought to be secreted instead via an unconventional protein secretion (UPS) pathway in a small vasohibin-binding protein (SVBP)-dependent manner. However, the precise mechanism of SVBP-dependent UPS is poorly understood. In this study, we identified a novel UPS regulatory system in which essential domain architecture (VASH-PS) of VASHs, comprising regions VASH1_91-180 and VASH2_80-169 , regulate the cytosolic punctate structure formation in the absence of SVBP. We also demonstrate that SVBP form a complex with VASH1 through the VASH1_274-282 (SIa), VASH1_139-144 (SIb), and VASH1_133-137 (SIc), leading to the dispersion in the cytosol and extracellular release of VASH1. The amino acid sequences of VASH-SIa and VASH-PS, containing SIb and SIc, are highly conserved among VASH family members in vertebrates, suggesting that SVBP-dependent UPS may be common within the VASH family. This novel UPS regulatory system may open up new avenues for understanding fundamental protein secretion in vertebrates.

Silencing speckle-type POZ protein by promoter hypermethylation decreases cell apoptosis through upregulating Hedgehog signaling pathway in colorectal cancer

Epigenetic silencing of tumor suppressors contributes to the development and progression of colorectal cancer (CRC). We recently found that speckle-type POZ protein (SPOP) was significantly downregulated and the inactivation of SPOP promoted metastasis in CRC. This study aimed to clarify its epigenetic alteration, molecular mechanisms and clinical significance in CRC. Our results revealed that the core region of SPOP promoter was hypermethylated in CRC tissues and its methylation was correlated with poor survival. Transcription factor RXRA had a vital role in the regulation of SPOP gene. The data indicated that DNA methylation at −167 bp of the SPOP gene altered the binding affinity between transcription factor RXRA and SPOP promoter. Moreover, SPOP was found to associate with Gli2 and promoted its ubiquitination and degradation in CRC. Consequently, the expression level of Hh/Gli2 pathway-related apoptotic protein Bcl-2 was decreased and the function of resisting cell death was inhibited in CRC. It suggests that methylation status of SPOP promoter can be used as a novel epigenetic biomarker and a therapeutic target in CRC.

Vasohibin 2 promotes epithelial-mesenchymal transition in human breast cancer via activation of transforming growth factor β 1 and hypoxia dependent repression of GATA-binding factor 3

Vasohibin 2 (VASH2) is identified as an angiogenic factor, and has been implicated in tumor angiogenesis, proliferation and epithelial-mesenchymal transition (EMT). To investigate the EMT role of VASH2 in breast cancer, we overexpressed or knocked down expression of VASH2 in human breast cancer cell lines. We observed that VASH2 induced EMT in vitro and in vivo. The transforming growth factor β1 (TGFβ1) pathway was activated by VASH2, and expression of a dominant negative TGFβ type II receptor could block VASH2-mediated EMT. In clinical breast cancer tissues VASH2 positively correlated with TGFβ1 expression, but negatively correlated with E-cadherin (a marker of EMT) expression. Under hypoxic conditions in vitro or in vivo, we found that down-regulation of estrogen receptor 1 (ESR1) in VASH2 overexpressing ESR1 positive cells suppressed E-cadherin. Correlation coefficient analysis indicated that VASH2 and ESR1 expression were negatively correlated in clinical human breast cancer tissues. Further study revealed that a transcription factor of ESR1, GATA-binding factor 3 (GATA3), was down-regulated by VASH2 under hypoxia or in vivo. These findings suggest that VASH2 drives breast cancer cells to undergo EMT by activation of the TGFβ1 pathway and hypoxia dependent repression GATA3-ESR1 pathway, leading to cancer metastasis.

Long non-coding RNA H19 regulates glioma angiogenesis and the biological behavior of glioma-associated endothelial cells by inhibiting microRNA-29a

Long non-coding RNAs (lncRNAs) play crucial roles in the development and progression of glioma. Previous studies indicated that lncRNA H19 regulated tumor carcinogenesis, angiogenesis and metastasis. This study aimed to investigate its functional role in glioma-induced endothelial cell proliferation, migration and tube formation as well as its possible molecular mechanisms. H19 was up-regulated in microvessels from glioma tissues and glioma-associated endothelial cells (GEC) cultured in glioma conditioned medium. Knockdown of H19 suppressed glioma-induced endothelial cell proliferation, migration and tube formation in vitro and meanwhile up-regulated the expression of miR-29a. Bioinformatics analysis and luciferase reporter assay defined that H19 mediated the above effects via directly binding to miR-29a. In addition, miR-29a targeted 3'-UTR region of vasohibin 2 (VASH2) and decreased its expression. VASH2 has been identified as an angiogenic factor. Knockdown of H19 also decreased the VASH2 expression by up-regulating miR-29a. In conclusion, the results indicated that knockdown of H19 suppressed glioma induced angiogenesis by inhibiting microRNA-29a, which may modulate the onset of glioma by regulating biological behaviors of glioma vascular endothelial cells.

Vasohibin-1 suppresses colon cancer

Vasohibin-1 (VASH1) is an endogenous angiogenesis inhibitor.However, the clinical relevance of VASH1 in colon cancer and its regulations on cancer angiogenesis and cancer cell biological characteristics are still unknown. Here we showed that stromal VASH1 levels were negatively correlated with tumor size, advanced clinical stage and distant metastases in colon cancer patients. Overexpression of VASH1 in colon cancer cells induced apoptosis and senescence, inhibiting cancer cell growth and colony formation in vitro and tumor growth in vivo. In addition, knockdown of VASH1 in cancer cells promoted cell growth, adhesion and migration in vitro, and enhanced tumorigenesis and metastasis in vivo.

Vasohibins: new transglutaminase-like cysteine proteases possessing a non-canonical Cys-His-Ser catalytic triad

Vasohibin-1 and Vasohibin-2 regulate angiogenesis, tumour growth and metastasis. Their molecular functions, however, were previously unknown, in large part owing to their perceived lack of homology to proteins of known structure and function. To identify their functional amino acids and domains, their molecular activity and their evolutionary history, we undertook an in-depth analysis of Vasohibin sequences. We find that Vasohibin proteins are previously undetected members of the transglutaminase-like cysteine protease superfamily, and all possess a non-canonical Cys-His-Ser catalytic triad. We further propose a calcium-dependent activation mechanism for Vasohibin proteins. These findings can now be used to design constructs for protein structure determination and to develop enzyme inhibitors as angiogenic regulators to treat metastasis and tumour growth.

CONTACT

luis.sanchezpulido@dpag.ox.ac.uk

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Protective role of gambogic acid in experimental pulmonary fibrosis in vitro and in vivo

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive disorder with poor prognosis. The treatment options for IPF are very limited. Gambogic acid (GA) has anticancer effect and anti-proliferative activity which is extracted from a dried yellow resin of the Garcinia hanburyi Hook.f. [Clusiaceae (Guttiferae)] in Southeast Asia. However, the anti-fibrotic activities of GA have not been previously investigated.

METHODS

In this study, the effects of GA on TGF-β1-mediated epithelial-mesenchymal transition (EMT) in A549 cells and endothelial-mesenchymal transition (EndoMT) in human pulmonary microvascular endothelial cells (HPMECs), on the proliferation of human lung fibroblasts (HLF-1) were investigated in vitro, and on bleomycin (BLM)-induced pulmonary fibrosis was investigated in vivo.

RESULTS

In TGF-β1 stimulated A549 cells, treatment with GA resulted in a reduction of EMT with a decrease in vimentin and p-Smad3 and an increase in E-cadherin instead. In TGF-β1 stimulated HPMECs, treatment with GA resulted in a reduction of EndoMT with a decrease in vimentin, and an increase in VE-cadherin instead. In the hypoxic HPMECs, treatment with GA reduced Vasohibin-2 (VASH-2), whereas increased VASH-1. In TGF-β1 stimulated HLF-1, treatment with GA reduced HLF-1 proliferation with a decrease in platelet-derived growth factor (PDGF) and fibroblast growth factor (FGF-2) expressions. In vivo, treatment with GA for 2 weeks resulted in an amelioration of the BLM-induced pulmonary fibrosis in rats with a lower VASH-2. Instead, it was observed a higher VASH-1 expression at early stage of fibrosis at 1 mg/kg, with reductions of the pathological score, collagen deposition, α-SMA, PDGF and FGF-2 expressions at fibrotic stage at 0.5 mg/kg and 1 mg/kg.

CONCLUSION

In summary, GA reversed EMT and EndoMT, as well as HLF-1 proliferation in vitro and prevented pulmonary fibrosis in vivo by modulating VASH-2/VASH-1 and suppressing the TGF-β1/Smad3 pathway.

SOX17 increases the cisplatin sensitivity of an endometrial cancer cell line

Background

Endometrial cancer (EC) is the most common form of malignant gynecological tumor. Treatment with cisplatin (CDDP) is the mainstay of EC chemotherapy. The apoptotic machinery is regarded as an important etiological factor in chemoresistance. Recent evidence has suggested that overexpression of the transcription factor SOX17 prevented apoptosis in tumor cell lines. The effect of SOX17 on apoptosis in EC cisplatin chemoresistance remains unclear.

Methods

Immunohistochemistry and the reverse transcription-polymerase chain reaction were employed to detect gene expression in paraffin-embedded EC tissues and blood samples. The anti-proliferative ability of SOX17 on EC cells was assessed by MTT. Flow cytometric analysis was used to detect cell apoptosis by annexin V/PI double-staining. The expression of apoptosis-related proteins was analyzed by western blot. In the in vivo study, nude mice were subcutaneously injected with EC cells, and received cisplatin treatment through intraperitoneal chemotherapy. Apoptosis of in vivo samples was analyzed by TUNEL assay.

Results

SOX17 expression decreased the chemical resistance of EC cells to CDDP. HEC-1B cells with an elevated expression of SOX17 had a lower cell viability and higher apoptosis rate after cisplatin exposure. Overexpression SOX17 up-regulated wild type p53 after being exposed to cisplatin, while the expression of BCL2-associated X protein and cleaved caspase-3 simultaneously increased. Caspase-9 inhibitor reduced the efficacy of SOX17 in HEC-1B cells after cisplatin treatment. In the in vivo study, SOX17 overexpression clearly restrained the tumor growth and increased the cisplatin toxicity and apoptosis of tumor cells.

Conclusions

SOX17 is involved in the p53-mediated apoptosis pathway, and increases the sensitivity of HEC-1B cells to cisplatin.

Electronic supplementary material

The online version of this article (doi:10.1186/s12935-016-0304-7) contains supplementary material, which is available to authorized users.

Ponatinib attenuates experimental pulmonary arterial hypertension by modulating Wnt signaling and vasohibin-2/vasohibin-1

AIMS

An abnormal ratio of vasohibin-2/vasohibin-1 may be involved in the abnormal angiogenesis and vascular remodeling during pulmonary arterial hypertension (PAH).

MAIN METHODS

To evaluate the pharmacological actions of Ponatinib (AP) in experimental model of PAH, the effects of AP on TGF-β1-mediated endothelial-mesenchymal transition (EndoMT) in human pulmonary microvascular endothelial cells (HPMEC), and the hypoxic human pulmonary artery smooth muscle cells (HPASMC) proliferation and HPMEC in vitro, and on bleomycin (BLM)-induced PAH in vivo were investigated.

KEY FINDINGS

AP treatment resulted in a reduction of EndoMT in HPMECs with a decrease of vimentin, whereas an increase of VE-cadherin, reduction of fibroblast growth factor (FGF-2), vascular endothelial growth factor (VEGF) and vasohibin-2 (VASH-2), whereas an increase of vasohibin-1 (VASH-1) in the hypoxic HPMEC, a reduction of the HPASMC proliferation with decreases of wnt5a, β-catenin and cyclin D1 expression. AP ameliorated BLM-induced PAH in rats with reductions of FGF-2, VEGF, von Willebrand factor (vWF) and VASH-2 expression, whereas an increase of VASH-1 expression. AP ameliorated BLM-induced PAH in rats with reductions of the pathological score and the collagen deposition. In addition, AP ameliorated hemodynamics and right ventricular hypertrophy.

SIGNIFICANCES

Our results identified a therapeutic potential of AP in PAH therapy might be modulated VASH-2/VASH-1 and the Wnt signaling.

miR-874 functions as a tumor suppressor by inhibiting angiogenesis through STAT3/VEGF-A pathway in gastric cancer

MicroRNAs are endogenously expressed, small non-coding RNAs that regulate gene expression by targeting mRNAs for translational repression or degradation. Our previous studies indicated that miR-874 played a suppressive role in gastric cancer (GC) development and progression. However, the role of miR-874 in tumor angiogenesis and the mechanisms underlying its function in GC remained to be clarified. Here, gain- and loss-of-function assays demonstrated that miR-874 inhibited the tumor angiogenesis of GC cells in vitro and in vivo. Through reporter gene and western blot assays, STAT3 was shown to be a direct target of miR-874. Overexpression of STAT3 rescued the loss of tumor angiogenesis caused by miR-874. Conversely, the STAT3-shRNA attenuated the increased tumor angiogenesis caused by the miR-874-inhibitor. Furthermore, the levels of miR-874 were inversely correlated with those of STAT3 protein in GC tissues. Taken together, these findings indicate that down-regulation of miR-874 contributes to tumor angiogenesis through STAT3 in GC, highlighting the potential of miR-874 as a target for human GC therapy.