Targeting VEGFR1- and VEGFR2-expressing non-tumor cells is essential for esophageal cancer therapy

Global comparative transcriptomes uncover novel and population-specific gene expression in esophageal squamous cell carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) has a poor prognosis and is one of the deadliest gastrointestinal malignancies. Despite numerous transcriptomics studies to understand its molecular basis, the impact of population-specific differences on this disease remains unexplored.

AIMS

This study aimed to investigate the population-specific differences in gene expression patterns among ESCC samples obtained from six distinct global populations, identify differentially expressed genes (DEGs) and their associated pathways, and identify potential biomarkers for ESCC diagnosis and prognosis. In addition, this study deciphers population specific microbial and chemical risk factors in ESCC.

METHODS

We compared the gene expression patterns of ESCC samples from six different global populations by analyzing microarray datasets. To identify DEGs, we conducted stringent quality control and employed linear modeling. We cross-compared the resulting DEG lists of each populations along with ESCC ATLAS to identify known and novel DEGs. We performed a survival analysis using The Cancer Genome Atlas Program (TCGA) data to identify potential biomarkers for ESCC diagnosis and prognosis among the novel DEGs. Finally, we performed comparative functional enrichment and toxicogenomic analysis.

RESULTS

Here we report 19 genes with distinct expression patterns among populations, indicating population-specific variations in ESCC. Additionally, we discovered 166 novel DEGs, such as ENDOU, SLCO1B3, KCNS3, IFI35, among others. The survival analysis identified three novel genes (CHRM3, CREG2, H2AC6) critical for ESCC survival. Notably, our findings showed that ECM-related gene ontology terms and pathways were significantly enriched among the DEGs in ESCC. We also found population-specific variations in immune response and microbial infection-related pathways which included genes enriched for HPV, Ameobiosis, Leishmaniosis, and Human Cytomegaloviruses. Our toxicogenomic analysis identified tobacco smoking as the primary risk factor and cisplatin as the main drug chemical interacting with the maximum number of DEGs across populations.

CONCLUSION

This study provides new insights into population-specific differences in gene expression patterns and their associated pathways in ESCC. Our findings suggest that changes in extracellular matrix (ECM) organization may be crucial to the development and progression of this cancer, and that environmental and genetic factors play important roles in the disease. The novel DEGs identified may serve as potential biomarkers for diagnosis, prognosis and treatment.

Raltitrexed enhanced antitumor effect of anlotinib in human esophageal squamous carcinoma cells on proliferation, invasiveness, and apoptosis

BACKGROUND

Anlotinib is a multi-targeted receptor tyrosine kinase inhibitor (TKI) which has exhibited encouraging clinical activity in advanced non-small cell lung cancer (NSCLC) and soft tissue sarcoma. Raltitrexed is well known to be effective in the treatment of colorectal cancer in China. The present study aims to investigate the combinatory antitumor effect of anlotinib and raltitrexed on human esophageal squamous carcinoma cells and further explore the molecular mechanisms in vitro.

METHODS

Human esophageal squamous cell lines KYSE-30 and TE-1 were treated with anlotinib or raltitrexed, or both, then cell proliferation was measured by MTS and colony formation assay; cell migration and invasion were detected by wound-healing and transwell assays; cell apoptosis rate was studied by flow cytometry and the transcription of apoptosis-associated proteins were monitored by quantitative polymerase chain reaction (qPCR) analysis. Finally, western blot was performed to check phosphorylation of apoptotic proteins after treatment.

RESULTS

Treatment with raltitrexed and anlotinib showed enhanced inhibitory effects on cell proliferation, migration and invasiveness compared with raltitrexed or anlotinib monotherapy. Meanwhile, raltitrexed combined with anlotinib strongly increased cell apoptosis percentage. Moreover, the combined treatment down-regulated mRNA level of the anti-apoptotic protein Bcl-2 and invasiveness-associated protein matrix metalloproteinases-9 (MMP-9), while up-regulated pro-apoptotic Bax and caspase-3 transcription. Western blotting showed that the combination of raltitrexed and anlotinib could inhibit the expression of phosphorylated Akt (p-Akt), Erk (p-Erk) and MMP-9.

CONCLUSIONS

This study indicated that raltitrexed enhanced the antitumor effects of anlotinib on human ESCC cells by down-regulating phosphorylation of Akt and Erk, providing a novel treatment option for patients with esophageal squamous cell carcinoma (ESCC).

Metastasis prevention: How to catch metastatic seeds

Despite considerable advances in the evolution of anticancer therapies, metastasis still remains the main cause of cancer mortality. Therefore, current strategies for cancer cure should be redirected towards prevention of metastasis. Targeting metastatic pathways represents a promising therapeutic opportunity aimed at obstructing tumor cell dissemination and metastatic colonization. In this review, we focus on preclinical studies and clinical trials over the last five years that showed high efficacy in suppressing metastasis through targeting lymph node dissemination, tumor cell extravasation, reactive oxygen species, pre-metastatic niche, exosome machinery, and dormancy.

lncRNA TPT1-AS1 promotes cell migration and invasion in esophageal squamous-cell carcinomas by regulating the miR-26a/HMGA1 axis

lncRNA TPT1-AS1 plays an oncogenic role in ovarian and cervical cancers. However, its involvement in the pathological progress of esophageal squamous-cell carcinomas (ESCCs) is unclear. lncRNA TPT1-AS1 was mainly localized in the cytoplasm of ESCC cells and interacted with miR-26a. In ESCC tissues, lncRNA TPT1-AS1 level was obviously increased, while miR-26a level was decreased. Interestingly, lncRNA TPT1-AS1 level was not significantly correlated with miR-26a level but was positively correlated with HMGA1 mRNA, a target of miR-26a. In ESCC cell lines KYSE510 and KYSE-30, lncRNA TPT1-AS1 overexpression enhanced HMGA1 expression, while it had no effect on miR-26a expression. Cell migration and proliferation assays indicated that lncRNA TPT1-AS1 and HMGA1 overexpression promoted ESCC cell migration and invasion, while their effects were alleviated by miR-26a overexpression. The migration and invasion of ESCC cells were suppressed by lncRNA TPT1-AS1 knockdown. In conclusion, lncRNA TPT1-AS1 plays an oncogenic role in ESCC and might function by upregulating HMGA1 via sponging miR-26a.

M6PR- and EphB4-Rich Exosomes Secreted by Serglycin-Overexpressing Esophageal Cancer Cells Promote Cancer Progression

Accumulating evidence shows that exosomes participate in cancer progression. However, the functions of cancer cell exosome-transmitted proteins are rarely studied. Previously, we reported that serglycin (SRGN) overexpression promotes invasion and metastasis of esophageal squamous cell carcinoma (ESCC) cells. Here, we investigated the paracrine effects of exosomes from SRGN-overexpressing ESCC cells (SRGN Exo) on ESCC cell invasion and tumor angiogenesis, and used mass spectrometry to identify exosomal proteins involved. Cation-dependent mannose-6-phosphate receptor (M6PR) and ephrin type-B receptor 4 (EphB4) were pronouncedly upregulated in SRGN Exo. Upregulated exosomal M6PR mediated the pro-angiogenic effects of SRGN Exo both in vitro and in vivo, while augmented exosomal EphB4 mediated the pro-invasive effect of SRGN Exo on ESCC cells in vitro. In addition, in vitro studies showed that manipulation of M6PR expression affected the viability and migration of ESCC cells. Both M6PR and EphB4 expression levels were positively correlated with that of SRGN in the serum of patients with ESCC. High level of serum M6PR was associated with poor overall survival rates. Taken together, this study presents the first proof that exosomal M6PR and EphB4 play essential roles in tumor angiogenesis and malignancy, and that serum M6PR is a novel prognostic marker for ESCC patients.

Ramucirumab combination with sorafenib enhances the inhibitory effect of sorafenib on HepG2 cancer cells

Sorafenib, an oral multiple kinase inhibitor, is the standardized treatment for hepatocellular carcinoma (HCC). One strategy to improve HCC therapy is to combine agents that target key signaling pathways. In this study we set out to investigate the effect of combining sorafenib with either bevacizumab (anti-VEGF), panitumumab (anti-EGFR) or ramucirumab (anti-VEGFR2) on HepG2 cancer cell line with the aim of improving efficacy and possibility of therapeutic dose reduction of sorafenib.: HepG2 cancer cell line was treated with sorafenib alone or in combination with either bevacizumab, panitumumab or ramucirumab. Cell proliferation; apoptosis and cell cycle distribution; gene expression of VEGFR2, EGFR, MMP-9 and CASPASE3; the protein levels of pVEGFR2 and pSTAT3 and the protein expression of CASPASE3, EGFR and VEGFR2 were determined. Combined treatments of sorafenib with ramucirumab or panitumumab resulted in a significant decrease in sorafenib IC₅₀. Sorafenib combination with ramucirumab or bevacizumab resulted in a significant arrest in pre-G and G0/G1 cell cycle phases, significantly induced apoptosis and increased the relative expression of CASPASE3 and decreased the anti-proliferative and angiogenesis markers´ MMP-9 and pVEGFR2 or VEGFR2 in HepG2 cells. A significant decrease in the levels of pSTAT3 was only detected in case of sorafenib-ramucirumab combination. The combined treatment of sorafenib with panitumumab induced a significant arrest in pre-G and G2/M cell cycle phases and significantly decreased the relative expression of EGFR and MMP-9. Sorafenib-ramucirumab combination showed enhanced apoptosis, inhibited proliferation and angiogenesis in HepG2 cancer cells. Our findings suggest that ramucirumab can be a useful as an adjunct therapy for improvement of sorafenib efficacy in suppression of HCC.

Modified Benzoxazole-Based VEGFR-2 Inhibitors and Apoptosis Inducers: Design, Synthesis, and Anti-Proliferative Evaluation

This work is one of our efforts to discover potent anticancer agents. We modified the most promising derivative of our previous work concerned with the development of VEGFR-2 inhibitor candidates. Thirteen new compounds based on benzoxazole moiety were synthesized and evaluated against three human cancer cell lines, namely, breast cancer (MCF-7), colorectal carcinoma (HCT116), and hepatocellular carcinoma (HepG2). The synthesized compounds were also evaluated against VEGFR-2 kinase activity. The biological testing fallouts showed that compound 8d was more potent than standard sorafenib. Such compound showed IC₅₀ values of 3.43, 2.79, and 2.43 µM against the aforementioned cancer cell lines, respectively, compared to IC₅₀ values of 4.21, 5.30, and 3.40 µM reported for sorafenib. Compound 8d also was found to exert exceptional VEGFR-2 inhibition activity with an IC₅₀ value of 0.0554 μM compared to sorafenib (0.0782 μM). In addition, compound 8h revealed excellent cytotoxic effects with IC₅₀ values of 3.53, 2.94, and 2.76 µM against experienced cell lines, respectively. Furthermore, compounds 8a and 8e were found to inhibit VEGFR-2 kinase activity with IC₅₀ values of 0.0579 and 0.0741 μM, exceeding that of sorafenib. Compound 8d showed a significant apoptotic effect and arrested the HepG2 cells at the pre-G1 phase. In addition, it exerted a significant inhibition for TNF-α (90.54%) and of IL-6 (92.19%) compared to dexamethasone (93.15%). The molecular docking studies showed that the binding pattern of the new compounds to VEGFR-2 kinase was similar to that of sorafenib.

The role of autophagy in initiation, progression, TME modification, diagnosis, and treatment of esophageal cancers

Autophagy is a highly conserved metabolic process with a cytoprotective function. Autophagy is involved in cancer, infection, immunity, and inflammation and may be a potential therapeutic target. Increasing evidence has revealed that autophagy has primary implications for esophageal cancer, including its initiation, progression, tumor microenvironment (TME) modification, diagnosis, and treatment. Notably, autophagy displayed excellent application potential in radiotherapy combined with immunotherapy. Radiotherapy combined with immunotherapy is a new potential therapeutic strategy for cancers, including esophageal cancer. Autophagy modulators can work as adjuvant enhancers in radiotherapy or immunotherapy of cancers. This review highlights the most recent data related to the role of autophagy regulation in esophageal cancer.

New Series of VEGFR-2 Inhibitors and Apoptosis Enhancers: Design, Synthesis and Biological Evaluation

Background

Cancer is still a major world health threat, causing a high rate of mortality. VEGFR-2 inhibitor anticancer agents are of great significance. However, they showed some serious side effects.

Purpose

To discover new effective and safer anticancer agents, a new series of piperazinylquinoxaline-based derivatives was designed and synthesized on the basis of the pharmacophoric features of VEGFR-2 inhibitor drugs.

Methods

The new candidates were evaluated against A549 lung cancer cells, HepG-2 hepatoma cells, Caco-2 colon cancer cells, MDA breast cancer cells, and VEGFR-2 kinase. Moreover, cell cycle kinetics and apoptosis rates were studied in HepG-2 cells treated with compound 11, which was the most promising candidate.

Results

The new derivatives revealed better antitumor results (IC₅₀ from 6.48 to 38.58 µM) against the aforementioned cancer cell lines than sorafenib. Also, the new candidates showed VEGFR-2 inhibition with IC₅₀ values ranging from 0.19 to 0.60 µM compared to 0.08 µM for sorafenib. Compound 11, meanwhile, showed IC₅₀ values equal to 10.61, 9.52, 12.45, 11.52, and 0.19 µM against the cancer cell lines and VEGFR-2, respectively. Moreover, compound 11 raised the apoptosis rate in HepG-2 cells from 5% to 44% and caused 4, 2.3, and 3-fold increases in BAX/Bcl-2 ratio, caspase-3 level, and P53 expression, respectively, compared to control untreated cells. Finally, the new derivatives displayed the correct binding mode into VEGFR-2 kinase pocket, giving interactions with the essential residues.

Conclusion

This work suggests that compound 11 is a very significant anticancer candidate, and piperazinylquinoxaline is an important scaffold in the development of new potential effective and safer VEGFR-2 inhibitor agents.

Spatial architecture of the immune microenvironment orchestrates tumor immunity and therapeutic response

Tumors are not only aggregates of malignant cells but also well-organized complex ecosystems. The immunological components within tumors, termed the tumor immune microenvironment (TIME), have long been shown to be strongly related to tumor development, recurrence and metastasis. However, conventional studies that underestimate the potential value of the spatial architecture of the TIME are unable to completely elucidate its complexity. As innovative high-flux and high-dimensional technologies emerge, researchers can more feasibly and accurately detect and depict the spatial architecture of the TIME. These findings have improved our understanding of the complexity and role of the TIME in tumor biology. In this review, we first epitomized some representative emerging technologies in the study of the spatial architecture of the TIME and categorized the description methods used to characterize these structures. Then, we determined the functions of the spatial architecture of the TIME in tumor biology and the effects of the gradient of extracellular nonspecific chemicals (ENSCs) on the TIME. We also discussed the potential clinical value of our understanding of the spatial architectures of the TIME, as well as current limitations and future prospects in this novel field. This review will bring spatial architectures of the TIME, an emerging dimension of tumor ecosystem research, to the attention of more researchers and promote its application in tumor research and clinical practice.

In Vitro Assays of Biological Aggressiveness of Esophageal Squamous Cell Carcinoma

Researchers are developing new techniques and technologies to determine the characteristic features for cancer progression, thereby identifying potential targets and therapeutics to interfere these hallmark processes of cancer pathogenesis. The transformative researches using these in vitro methods have enable researchers to design precision treatments of patients with esophageal squamous cell carcinoma (ESCC). These in vitro methods mainly include analysis of cell proliferation, cytotoxicity, colony formation, invasion, and migration in ESCC cells for analyzing manipulations affecting the biological behavior of ESCC. Because of these studies, important information on molecular mechanisms of different genes and proteins as well as result of therapeutic interventions are confirmed in ESCC.

Clinical efficacy and safety of apatinib as maintenance treatment in patients with advanced esophageal squamous cell carcinoma

Background: To investigate the clinical efficacy, safety and prognostic factors of apatinib therapy as maintenance treatment in patients with advanced esophageal squamous cell carcinoma. Methods: We selected 46 patients with advanced esophageal squamous cell carcinoma treated with radiotherapy and chemotherapy in our hospital from January 2017 to February 2019, all of whom were treated with apatinib. We analyzed the clinical efficacy, adverse reactions and prognostic factors. Meanwhile, the expression of VEGFR-2 and NF-kB was detected by the immunohistochemical SABC method. Results: The oral treatment of apatinib in the VEGFR-2 and NF-kB positive groups was better than that in the negative groups. The disease control rate was 67.39%. The main adverse reactions were hypertension (60.87%). The degree of adverse reactions was mainly grade 1-2. Cox multivariate regression analysis showed that the degree of adverse reactions and ECOG score were independent factors affecting OS in patients with advanced esophageal squamous cell carcinoma. Conclusion: The positive expression of VEGFR-2 and NF-kB is expected to be the molecular target of oral apatinib targeted therapy for esophageal cancer. Apatinib has a certain clinical effect as the maintenance treatment for advanced esophageal squamous cell carcinoma patients, with mild adverse reactions and high safety.

Raltitrexed Enhances the Antitumor Effect of Apatinib in Human Esophageal Squamous Carcinoma Cells via Akt and Erk Pathways

Objective

Apatinib has been proved effective in the treatment of advanced gastric cancer and a variety of solid tumors. Raltitrexed is emerging as a promising alternative for treating advanced colorectal cancer in China. This work aims to study the combinatory antitumor effect of apatinib and raltitrexed on human esophageal squamous carcinoma cells (ESCC).

Materials and Methods

Two VEGFR-2-positive human ESCC lines, KYSE-30 and TE-1, were treated with apatinib or raltitrexed, or both, then the cell proliferation rate was measured by MTS assay; cell migration and invasion were studied by transwell assays; cell apoptosis rate was determined by flow cytometry; cellular autophagy level affected was analyzed by Western blot analysis; finally, quantitative polymerase chain reaction (qPCR) was used to monitor transcription and Western blot was performed to check phosphorylation of apoptotic proteins after treatment.

Results

Both apatinib and raltitrexed significantly inhibited KYSE-30 and TE-1 cell proliferation in a dose-dependent manner. Treatment with both drugs showed enhanced inhibitory effects on cell proliferation, migration, and invasiveness compared with apatinib monotherapy. Apoptosis percentages in both cell lines were also remarkably increased by the combined treatment. Moreover, the combination of apatinib and raltitrexed down-regulated mRNA level of the anti-apoptotic protein Bcl-2, while up-regulated pro-apoptotic protein PARP, Bax, and caspase-3 transcription. Western blot analysis showed that phosphorylation levels of Erk, Akt, and invasiveness-associated protein matrix metalloproteinases-9 (MMP-9) were decreased in the combination group.

Conclusion

Taken together, these results indicate that raltitrexed enhances the antitumor effects of apatinib on human ESCC cells by down-regulating phosphorylation of Akt and Erk, implying a combination of raltitrexed and apatinib might be an effective option for treating esophageal squamous cell carcinoma patients.

Potential Role of Targeting KDR and Proteasome Inhibitors in the Therapy of Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive cancer types in China. In recent years, progress has been made in various types of cancer genomics including ESCC. However, the clinical significance of genomic variation of ESCC remains poorly defined. In the present study, genomic sequencing data from 469 ESCC cases were analyzed and potential therapeutic targets in the Druggable Genome Interaction Database (DGIdb) were screened. A series of potential therapeutic target genes and pathways were identified, of which treatment of ESCC with bortezomib (a specific inhibitor targeting proteasome) potently inhibited the proliferation of 5 ESCC cell lines and administration of bortezomib led to significant tumor xenograft regression in SCID mice. It was also identified that kinase insert domain receptor (KDR), which had drug recommendations from all 6 sources integrated by the DGldb and harbored significant amplification in ESCC, might be a downstream target of zinc finger protein 750 (ZNF750). ZNF750 acts as a transcription factor and has been demonstrated to harbor frequently inactivating mutations in ESCC by previous independent studies. In the present study, KDR was upregulated upon ZNF750 knockdown and the rescue of ZNF750 also led to marked restoration of KDR. KDR knockdown in stable ZNF750-knockdown KYSE150 and KYSE140 ESCC cells significantly attenuated the promotion of cell growth, colony formation, invasion and migration induced by ZNF750 knockdown. Further experiments found that apatinib treatment, a potent inhibitor of KDR, resulted in profound inhibition of cell proliferation and invasion. Collectively, the present study provided insight for genomic alterations as potential therapeutic targets in ESCC and supported the possibility of a therapeutic strategy targeting the proteasome in ESCC. The present results also suggested that targeting KDR may be an effective way to treat ESCC, not only in KDR variant cases, but also in individuals with ZNF750 mutations and deletions.

Molecular mechanisms of synergistic action of Ramucirumab and Paclitaxel in Gastric Cancers cell lines

Ramucirumab is approved both as monotherapy and in combination with Paclitaxel for advanced gastric cancer in patients with disease progression after chemotherapy. In tumor cells, the VEGFA-VEGFR2 binding activates autocrine survival and migration signaling in angiogenesis independent manner. The present in vitro study investigated the effects of single and combined treatments with Ramucirumab and Paclitaxel on cell growth and migration highlighting the mechanisms underlying the interaction between the two drugs in gastric cancer cells. Cell growth and motility were investigated in human gastric cancer cell lines characterized by different tumorigenicity. The inhibitory effect on cell growth exerted by both drugs was potentiated by their combination and was synergistic. Ramucirumab was able to enhance the inhibitory effect exerted by Paclitaxel on cell cycle progression. A synergistic action was also observed in the expression of proteins crucial for cell motility, microtubule organization and epithelial-mesenchymal transition. Furthermore, synergistic inhibition of VEGFR2 expression was obtained by the drug combination. These findings highlighted the importance of the combined treatment to strongly inhibit all the main molecules of both PI3K/Akt/mTOR and MAPK pathways thus preventing possible reactivations due to cross-talk phenomena. The combined treatment with Ramucirumab seems to be a promising option to overcome the Paclitaxel resistance.

Whole-Slide Imaging of Esophageal Squamous Cell Carcinoma

Whole-slide imaging (WSI) contributes to medical education, collaboration, quality assurance, examination, and consultation in pathology. The images obtained from WSI are of high quality and could be stored indefinitely. In research involving esophageal squamous cell carcinoma, the combination of WSI and image processing program allows effective interpretations of expressions of various immunomarkers related to pathogenesis, prognosis, and response to therapy in tissue microarray sections. The operation and basic principles of whole-slide imaging of esophageal squamous cell carcinoma are also presented. Common use of WSI will occur with modifications of the whole-slide imaging scanners to adapt to the workflows in diagnostic and research laboratories.

Immunohistochemistry for Protein Detection in Esophageal Squamous Cell Carcinoma

Immunohistochemistry is the identification of a cell protein by a specific antibody targeting that protein. It is the most common ancillary test to study the pathology of cancer. Immunohistochemical protein markers are used to differentiate poorly differentiated squamous cell carcinoma from poorly differentiated adenocarcinoma or neuroendocrine carcinomas. They could be used to identify and type the carcinoma in metastatic locations. Importantly, immunodetection of markers also helps in prediction of response to therapies as well as assessing the different biomarkers related to the pathogenesis and clinical behavior of esophageal squamous cell carcinoma. Successful application of the immunochemistry depends on understanding the mechanisms and principles as well as the limitations of the procedure. Automation of the procedure by different models of automatic stainers is widely used in diagnostic laboratories. The use of autostainers streamlines the workflows and certainly reduces the labor, time, and cost of using immunohistochemistry in clinical and research settings.

Clinical efficacy and safety of apatinib combined with S-1 in advanced esophageal squamous cell carcinoma

Background Esophageal cancer is a very common malignant tumor in China, especially esophageal squamous cell carcinoma (ESCC), but there is currently no effective treatment for patients after first-line chemotherapy failure. Apatinib has shown promising outcomes in treatment with various solid tumors. Objectives To evaluate the clinical efficacy and safety of apatinib combined with S-1 in the treatment of advanced ESCC patients after first-line chemotherapy failure. Methods In this prospective study, fifteen patients with advanced ESCC who failed first-line chemotherapy were enrolled from Nov 2016 to Apr 2019. Patients received the combination therapy with apatinib (250-500 mg, once daily) plus S-1 (40–60 mg based on body surface area, twice daily). Primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), disease control rate (DCR) and objective response rate (ORR). Adverse events (AEs) were recorded to evaluate the safety. Results A total of 12 patients were included in the efficacy analysis. The median PFS was 6.23 months, and the median OS was 8.83 months. Two (16.67%) patients achieved partial remission, 9 patients (75.00%) achieved stable disease and 1 (8.33%) patient achieved progressive disease. DCR and ORR was 91.67%and 16.67%, respectively. Most frequent AEs were hypertension, myelosuppression, weakness, hemorrhage, hand-foot syndrome, total bilirubin elevation, sick, proteinuria, oral ulcer, loss of appetite, and transaminase elevation. The most AEs were in grade I~II. Conclusion The combination therapy of apatinib plus S-1 was effective and well tolerated in the treatment of advanced ESCC patients after first-line chemotherapy failure. The combination therapy has the potential to be a potent therapeutic option for advanced ESCC patients after first-line chemotherapy failure.

Monoclonal antibody AC10364 inhibits cell proliferation in 5-fluorouracil resistant hepatocellular carcinoma via apoptotic pathways

Background

This study was designed to investigate the antitumor activity of the mAb (AC10364) in vitro and elucidate the related mechanisms of inhibition to cell growth using bel/fu cells treated with AC10364.

Methods

The inhibitory effects of AC10364 on the proliferation of Bel/fu cells were examined using a cytotoxicity assay. Apoptosis of Bel/fu cells was detected using FITC annexin V and PI staining following treatment with AC10364 for 24 h. The factors regulating apoptosis were identified by Western blot using lysates of Bel/fu cells treated with AC10364 for 0, 12, 24, or 36 h. Genes associated with tumorigenesis or growth were analyzed by reverse transcription–quantitative polymerase chain reaction using Bel/fu cells treated for 12, 24, or 36 h with AC10364.

Results

The early apoptotic ratios of Bel/fu cells treated with AC10364 increased in a dose-dependent manner. The levels of caspases, including cleaved caspase-3, caspase-3 and caspase-9, were significantly high in Bel/fu cells treated with AC10364 (P<0.001). Compared with untreated cells, those exposed to AC10364 had showed significant downregulation of the expression of binding protein gene (G protein subunit α 15, GNA15) and other protein-coding genes, including fms-related tyrosine kinase 1(FLT1), nicotinamide phosphoribosyltransferase (NAMPT), netrin 4 (NTN4), platelet-derived growth factor subunit A (PDGFA), S100 calcium binding protein A11 (S100A11), tubulin β 3 class III (TUBB3), aldo-keto reductase family 1 member C3 (AKR1C3), endothelial PAS domain protein 1 (EPAS1), and interferon α-inducible protein 27 (IFI27) (P<0.001). Two other genes, AXL receptor tyrosine kinase (AXL) and carboxypeptidase A4 (CPA4), were significantly upregulated (P<0.001).

Conclusion

AC10364 inhibited cell viability and proliferation through aberrant expression of multiple genes associated with tumorigenesis or growth, which suggests that these genes may be promising therapeutic candidates for cancer therapy.

New emerging roles of CD133 in cancer stem cell: Signaling pathway and miRNA regulation

Cancer stem cells (CSC) are rare immortal cells within a tumor that are able to initiate tumor progression, development, and resistance. Advances studies show that, like normal stem cells, CSCs can be both self-renewed and given rise to many cell types, therefore form tumors. A number of cell surface markers, such as CD44, CD24, and CD133 are frequently used to identify CSCs. CD133, a transmembrane glycoprotein, either alone or in collaboration with other markers, has been mainly considered to identify CSCs from different solid tumors. However, the exactness of CD133 as a cancer stem cell biomarker has not been approved yet. The clinical importance of CD133 is as a CSC marker in many cancers. Also, it contributes to shorter survival, tumor progression, and tumor recurrence. The expression of CD133 is controlled by many extracellular or intracellular factors, such as tumor microenvironment, epigenetic factors, signaling pathways, and miRNAs. In this study, it was attempted to determine: 1) CD133 function; 2) the role of CD133 in cancer; 3) CD133 regulation; 4) the therapeutic role of CD133 in cancers.

FAM134B promotes esophageal squamous cell carcinoma in vitro and its correlations with clinicopathologic features

Family with sequence similarity 134, member B (FAM134B) is an autophagy regulator of endoplasmic reticulum first discovered to be involved in the pathogenesis of esophageal squamous cell carcinoma (ESCC). The present study examined the functional behavior of FAM134B in cancer cells and the association of FAM134B expression with clinicopathologic factors in patients with ESCC. Expression at both the mRNA and protein levels was investigated using real-time polymerase chain reaction and immunohistochemistry. The results were correlated with the clinical and pathological features of the patients. In addition, in vitro functional assays were used to investigate the roles of FAM134B in ESCC cells in response to gene silencing with shRNA lentiviral particles. Overexpression of FAM134B mRNA and protein was present in 31.2% (n = 29/93) and 36.6% (n = 41/112), respectively, in tumors, whereas downregulation occurred in 39.8% (n = 37/93) and 63.4% (n = 71/112), respectively. Expression of FAM134B protein in ESCC correlated with histologic grade (P = .002) and pathologic stage (P = .012). In vitro suppression of FAM134B in ESCC induced significant reductions of cell proliferation and colony formation (P < .05). In addition, suppression of FAM134B caused reduction of wound healing, migration, and invasion capacities of ESCC. To conclude, FAM134B could play crucial roles in the initiation and progression of ESCC, and FAM134B protein expression has potential predictive value. Therefore, development of strategies targeting FAM134B could have therapeutic value in the management of patients with ESCC.

Identification of miR-29c and its Target FBXO31 as a Key Regulatory Mechanism in Esophageal Cancer Chemoresistance: Functional Validation and Clinical Significance

Rationale: Dysregulated microRNA (miRNA) expressions in cancer can contribute to chemoresistance. This study aims to identify miRNAs that are associated with fluorouracil (5-FU) chemoresistance in esophageal squamous cell carcinoma (ESCC). The potential of miR-29c as a novel diagnostic, prognostic and treatment-predictive marker in ESCC, and its mechanisms and therapeutic implication in overcoming 5-FU chemoresistance were explored. Methods: The miRNA profiles of an ESCC cell model with acquired chemoresistance to 5-FU were analyzed using a Taqman miRNA microarray to identify novel miRNAs associated with 5-FU chemoresistance. Quantitative real-time PCR was used to determine miR-29c expression in tissue and serum samples of patients. Bioinformatics, gain- and loss-of-function experiments, and luciferase reporter assay were performed to validate F-box only protein 31 (FBXO31) as a direct target of miR-29c, and to identify potential transcription factor binding events that control miR-29c expression. The potential of systemic miR-29c oligonucleotide-based therapy in overcoming 5-FU chemoresistance was evaluated in tumor xenograft model. Results: MiR-29c, under the regulatory control of STAT5A, was frequently downregulated in tumor and serum samples of patients with ESCC, and the expression level was correlated with overall survival. Functional studies showed that miR-29c could override 5-FU chemoresistance in vitro and in vivo by directly interacting with the 3'UTR of FBXO31, leading to repression of FBXO31 expression and downstream activation of p38 MAPK. Systemically administered miR-29c dramatically improved response of 5-FU chemoresistant ESCC xenografts in vivo. Conclusions: MiR-29c modulates chemoresistance by interacting with FBXO31, and is a promising non-invasive biomarker and therapeutic target in ESCC.

MiR-139-5p regulates VEGFR and downstream signaling pathways to inhibit the development of esophageal cancer

BACKGROUND

MiR-139-5p plays a significant role in tumorigenesis, metastasis and recurrence, suggesting that it may potentially be used as a promising biomarker for esophageal cancer diagnosis, prognosis and therapy. This study aimed to investigate the role and the mechanism of miRNA-139-5p in esophageal cancer.

METHODS

This study included 11 patients from an area with a high incidence of esophageal cancer. The expression levels of miRNA-139-5p in esophageal cancer tissues and para-carcinoma tissues of 11 patients were measured. We examined the expression of miR-139-5p in serum obtained from 92 consecutive patients from Cixian, which is a region in Hebei Province with a high rate of histologically confirmed esophageal cancer. The expression of miR-139-5p in esophageal cancer cell lines was detected. In the KYSE150 cell line with the lowest expression level of miR-139-5p, we transfected a plasmid to upregulate the expression level and examined the role of miR-139-5p in esophageal squamous cell carcinoma proliferation, migration and invasion. We conducted a gene profiling study using miR-139-5p cell lines to detect the expression of significant genes related to tumor progression, including cyclinD1, E-cadherin and VEGFR-1. We then constructed luciferase reporters containing miR-139-5p, which contained wild-type (WT) or mutated-type (Mut) VEGFR-1 binding sites to investigate the target.

RESULTS

MiRNA-139-5p expression levels in esophageal cancer tissues from 11 patients were significantly higher than those in para-carcinoma tissues. MiR-139-5p expression in the serum of 92 patients with esophageal cancer was associated with gender (P = 0.039) and TNM stage (P = 0.015). Factors that were not correlated with miR-139-5p expression were age (P = 0.293), smoking history (P = 0.397), length of tumor (P = 0.309), width of tumor (P = 0.296), depth of tumor (P = 0.724), lymphoma metastasis (P = 0.531) and postoperative therapy (P = 0.884). MiR-139-5p (P = 0.013) correlated significantly with observed survival rates. The lymphoma metastasis (P = 0.005) and TNM stage (P = 0.000) were significantly associated with observed survival rates. However, no significant relationships were found between the miR-139-5p and patient characteristics including gender, age, smoking history, tumor size and postoperative therapy. In the KYSE150 cell line, the expression level of miR-139-5p was the lowest. We transfected a plasmid to upregulate the expression level and found that the cell proliferation, metastasis and invasion abilities decreased. Upregulation of miR-139-5p inhibited the expression of Cyclin D1 and VEGFR-1 and increased the expression of E-cadherin. For further confirmation, we constructed luciferase reporters containing miR-139-5p, which contained wild-type (WT) or mutated-type (Mut) VEGFR-1 binding sites for target investigation. The results show that the corresponding VEGFR-1-Mut construct no longer suppressed miR-139-5p.

CONCLUSIONS

MiR-139-5p may be a novel therapeutic target and prognostic biomarker of esophageal cancer.

Synephrine Hydrochloride Suppresses Esophageal Cancer Tumor Growth and Metastatic Potential through Inhibition of Galectin-3-AKT/ERK Signaling

A library consisting of 429 food-source compounds was used to screen the natural products with anticancer properties in esophageal squamous cell carcinoma (ESCC). We demonstrated for the first time that synephrine, an active compound isolated from leaves of citrus trees, markedly suppressed cell proliferation (inhibition rate with 20 μM synephrine at day 5:71.1 ± 5.8% and 75.7 ± 6.2% for KYSE30 and KYSE270, respectively) and colony formation (inhibition rate with 10 μM synephrine: 86.5 ± 5.9% and 82.3 ± 4.5% for KYSE30 and KYSE270, respectively), as well as migration (inhibition rate with 10 μM synephrine: 76.9 ± 4.4% and 62.2 ± 5.8% for KYSE30 and KYSE270, respectively) and invasion abilities (inhibition rate with 10 μM synephrine: 73.3 ± 7.5% and 75.3 ± 3.4% for KYSE30 and KYSE270, respectively) of ESCC cells in a dose-dependent manner, without significant toxic effect on normal esophageal epithelial cells. Mechanistically, quantitative proteomics and bioinformatics analyses were performed to explore the synephrine-regulated proteins. Western blot and qRT-PCR data indicated that synephrine may downregulate Galectin-3 to inactivate AKT and ERK pathways. In addition, we found that the sensitivity of ESCC to fluorouracil (5-FU) could be enhanced by synephrine. Furthermore, in vivo experiments showed that synephrine had significant antitumor effect on ESCC tumor xenografts in nude mice (inhibition rate with 20 mg/kg synephrine is 61.3 ± 20.5%) without observed side effects on the animals. Taken together, synephrine, a food-source natural product, may be a potential therapeutic strategy in ESCC.

Survivin is critically involved in VEGFR2 signaling-mediated esophageal cancer cell survival

Vascular endothelial growth factor (VEGF) signaling promotes angiogenesis by stimulating the migration and proliferation of endothelial cells. The aim of this study was to investigate the expression of Survivin and VEGF receptor 1/2/3 (VEGFR 1/2/3) in esophageal carcinoma tissues (ECTs), and to explore the therapy effect of the suppression of VEGFR2 signaling. Here, we found that VEGFR2 and Survivin had high expressions and a significant correlation (r = 0.874, P < 0.002) in ECTs. Further, we found that VEGFR2 signaling could activate the AKT1/MDM2/Survivin pathway. The inhibition of VEGFR2 signaling with the XL184 treatment downregulated the phosphorylation of AKT1 and MDM2, and then, increased the activation of Caspase 3/7, resulting in the reduction of cell viability and the apoptosis of HUVECs. Additionally, in the esophageal tumor model, the tumor growth was significantly suppressed by blocking Survivin and the suppression of tumor growth was more effective in the combined treatment by blocking Survivin and Bcl-xl/Bcl-2. Our data thus revealed that Survivin in the signal downstream of VEGFR2 played an important role in esophageal cancer cell survival and might be a potential candidate target for the combined therapy for esophageal cancer.

Significance of PI3K/AKT signaling pathway in metastasis of esophageal squamous cell carcinoma and its potential as a target for anti-metastasis therapy

Metastasis is the most lethal hallmark of esophageal squamous cell carcinoma (ESCC). The aim of the study is to identify key signaling pathways that control metastasis in ESCC. Highly invasive ESCC sublines (designated I3 cells) were established through three rounds of selection of cancer cells invading through matrigel-coated chambers. Gene expression profile of one of the I3 sublines was compared with that of its parental cell line using cDNA microarray analysis. Gene ontology and pathway analyses of the differentially expressed genes (both upregulated and downregulated) indicated that genes associated with cellular movement and the AKT pathway were associated with increased cancer cell invasiveness. Western blot analysis confirmed increased phosphorylated AKT (p-AKT), N-cadherin and decreased E-cadherin expression in the I3 cells. Immunohistochemistry was used to evaluate the clinical significance of p-AKT expression in ESCC, and the results showed higher p-AKT nuclear expression in lymph node metastases when compared with primary carcinoma. Inactivation of the PI3K/AKT pathway with specific inhibitors, or with PTEN overexpression, resulted in reversed cadherin switching and inhibited cancer cell motility. Inhibition of the pathway by treatment with wortmannin markedly suppressed experimental metastasis in nude mice. Our data demonstrated the importance of the PI3K/AKT signaling pathway in ESCC metastasis and support PI3K/AKT as a valid therapeutic target in treatment of metastatic ESCC.

miR-205 targets angiogenesis and EMT concurrently in anaplastic thyroid carcinoma

The current study aims to evaluate for the first time the inhibitory roles of miR-205 in the pathogenesis of anaplastic thyroid carcinoma. In addition, we investigated the mechanisms by which miR-205 regulates angiogenesis and epithelial-to-mesenchymal transition (EMT) in cancer. Two anaplastic thyroid carcinoma cell lines were transfected with the expression vector pCMV-MIR-205 Selected markers of angiogenesis and EMT including vascular endothelial growth factor A (VEGF-A) and zinc finger E-box-binding homeobox 1 (ZEB1) were investigated by Western blot. The interaction of miR-205 expression with EMT and angiogenesis were also investigated by assessment of matrix metalloproteinases 2 and 9 (MMP2 and MMP 9), SNAI1 (Snai1 family zinc finger 1), vimentin, E-cadherin and N-cadherin. The function of miR-205 was further tested with VEGF enzyme-linked immunosorbent assay (ELISA), wound healing, invasion and tube formation assays. Using an animal model, we studied the association of miR-205 with angiogenesis, proliferation and invasion. The following results were obtained. Permanent overexpression of miR-205 significantly suppressed angiogenesis and EMT by simultaneously targeting VEGF-A, ZEB1 and downstream products. Ectopic expression of miR-205 in cancer cells led to decreased migration, invasion and tube formation of endothelial cells. In addition, inhibition of tumour growth, vascularisation and invasion were noted in the mouse tumour xenografts. Our findings provide insights into simultaneous regulatory role of miR-205 in the pathogenesis of anaplastic thyroid carcinoma by suppressing both angiogenesis and EMT. This may open avenues to exploit miR-205 as an alternative cancer therapeutic strategy in the future.

Expression, regulation and targeting of receptor tyrosine kinases in esophageal squamous cell carcinoma

Esophageal cancer is one of the most common types of cancer, which is a leading cause of cancer-related death worldwide. Based on histological behavior, it is mainly of two types (i) Esophageal squamous cell carcinoma (ESCC), and (ii) esophageal adenocarcinoma (EAD or EAC). In astronomically immense majority of malignancies, receptor tyrosine kinases (RTKs) have been kenned to play a consequential role in cellular proliferation, migration, and metastasis of the cells. The post-translational modifications (PTMs) including phosphorylation of tyrosine (pY) residue of the tyrosine kinase (TK) domain have been exploited for treatment in different malignancies. Lung cancer where pY residues of EGFR have been exploited for treatment purpose in lung adenocarcinoma patients, but we do not have such kind of felicitously studied and catalogued data in ESCC patients. Thus, the goal of this review is to summarize the studies carried out on ESCC to explore the role of RTKs, tyrosine kinase inhibitors, and their pertinence and consequentiality for the treatment of ESCC patients.

Expression, regulation and targeting of receptor tyrosine kinases in esophageal squamous cell carcinoma

Esophageal cancer is one of the most common types of cancer, which is a leading cause of cancer-related death worldwide. Based on histological behavior, it is mainly of two types (i) Esophageal squamous cell carcinoma (ESCC), and (ii) esophageal adenocarcinoma (EAD or EAC). In astronomically immense majority of malignancies, receptor tyrosine kinases (RTKs) have been kenned to play a consequential role in cellular proliferation, migration, and metastasis of the cells. The post-translational modifications (PTMs) including phosphorylation of tyrosine (pY) residue of the tyrosine kinase (TK) domain have been exploited for treatment in different malignancies. Lung cancer where pY residues of EGFR have been exploited for treatment purpose in lung adenocarcinoma patients, but we do not have such kind of felicitously studied and catalogued data in ESCC patients. Thus, the goal of this review is to summarize the studies carried out on ESCC to explore the role of RTKs, tyrosine kinase inhibitors, and their pertinence and consequentiality for the treatment of ESCC patients.

Advances in studies of tyrosine kinase inhibitors and their acquired resistance

Protein tyrosine kinase (PTK) is one of the major signaling enzymes in the process of cell signal transduction, which catalyzes the transfer of ATP-γ-phosphate to the tyrosine residues of the substrate protein, making it phosphorylation, regulating cell growth, differentiation, death and a series of physiological and biochemical processes. Abnormal expression of PTK usually leads to cell proliferation disorders, and is closely related to tumor invasion, metastasis and tumor angiogenesis. At present, a variety of PTKs have been used as targets in the screening of anti-tumor drugs. Tyrosine kinase inhibitors (TKIs) compete with ATP for the ATP binding site of PTK and reduce tyrosine kinase phosphorylation, thereby inhibiting cancer cell proliferation. TKI has made great progress in the treatment of cancer, but the attendant acquired acquired resistance is still inevitable, restricting the treatment of cancer. In this paper, we summarize the role of PTK in cancer, TKI treatment of tumor pathways and TKI acquired resistance mechanisms, which provide some reference for further research on TKI treatment of tumors.

CD24 promoted cancer cell angiogenesis via Hsp90-mediated STAT3/VEGF signaling pathway in colorectal cancer

CD24 is involved in tumor progression of various cancers, but the effects of CD24 on tumor angiogenesis in colorectal cancer are still unknown. We aimed to investigate the underlying mechanism and role of CD24 on colorectal cancer (CRC) angiogenesis. Our data showed that the microvessal density (MVD) was related to the expression of CD24 in primary and metastasis CRC. Silencing of CD24 could dramatically decrease human umbilical vein endothelial cell (HUVEC) migration, invasion and tubule formation, but trivially affected cell proliferation. We also mechanically showed that silencing CD24 could downregulate the expression of VEGF via inhibiting the phosphorylation and translocation of STAT3. Moreover, Hsp90 was identified as the down-interaction protein of CD24 with co-immunoprecipitation assay and systematic mass spectrometry. Immunofluorescence results showed Hsp90 partly co-localized with CD24 in CRC cell membrane and there was a positive correlation between CD24 and Hsp90 expression in CRC tissues. We gradually evidenced that Hsp90 modulated the stability and degradation of CD24 in a proteasome-depended manner, and transferred the signal transmission from CD24 to STAT3. 17-AAG, a specific Hsp90, could abrogate the CD24 induce- HUVEC migration, invasion and tubule formation in vitro and in vivo. Collectively, our results suggested that CD24 induced CRC angiogenesis in Hsp90-dependent manner and activated STAT3-mediated transcription of VEGF. We provided a new insight into the regulation mechanism of tumor angiogenesis by exploring the role of CD24 in angiogenesis.

VEGFR2 targeted antibody fused with MICA stimulates NKG2D mediated immunosurveillance and exhibits potent anti-tumor activity against breast cancer

Binding of MHC class I-related chain molecules A and B (MICA/B) to the natural killer (NK) cell receptor NK group 2, member D (NKG2D) is thought critical for activating NK-mediated immunosurveillance. Angiogenesis is important for tumor growth and interfering with angiogenesis using the fully human IgG1 anti-VEGFR2 (vascular endothelial growth factor receptor 2) antibody (mAb04) can be effective in treating malignancy. In an effort to make mAb04 more effective we have generated a novel antibody fusion protein (mAb04-MICA) consisting of mAb04 and MICA. We found that mAb04-MICA maintained the anti-angiogenic and antineoplastic activities of mAb04, and also enhanced immunosurveillance activated by the NKG2D pathway. Moreover, in human breast tumor-bearing nude mice, mAb04-MICA demonstrated superior anti-tumor efficacy compared to combination therapy of mAb04 + Docetaxel or Avastin + Docetaxel, highlighting the immunostimulatory effect of MICA. In conclusion, mAb04-MICA provided new inspiration for anti-tumor treatment and had prospects for clinical application.

The clinical and biological roles of transforming growth factor beta in colon cancer stem cells: A systematic review

BACKGROUND

Transforming growth factor beta (TGF-β) is a multipurpose cytokine, which plays a role in many cellular functions such as proliferation, differentiation, migration, apoptosis, cell adhesion and regulation of epithelial to mesenchymal transition. Despite many studies having observed the effect that TGF-β plays in colorectal cancer, its role in the colorectal stem cell population has not been widely observed.

METHOD

This systematic review will analyse the role of TGF-β in the stem cell population of colorectal cancer.

RESULTS

The effects on the stem cell phenotype are through the downstream proteins involved in activation of the TGF-β pathway. Its involvement in the initiation of the epithelial to mesenchymal transition (EMT), the effect of colorectal invasion and metastasis regulated through the Smad protein involvement in the EMT, initiation of angiogenesis, promotion of metastasis of colorectal cancer to the liver and its ability to cross-talk with other pathways.

CONCLUSION

TGF-β is a key player in angiogenesis, tumour growth and metastasis in colon cancer.

Comparative Proteomics Analysis Identifies Cdc42-Cdc42BPA Signaling as Prognostic Biomarker and Therapeutic Target for Colon Cancer Invasion

Metastasis is one of the major causes of treatment failure in the patients with colon cancer. The aim of our study is to find key proteins and pathways that drive invasion and metastasis in colon cancer. Eight rounds of selection of cancer cells invading through matrigel-coated chamber were performed to obtain highly invasive colon cancer sublines HCT116-I8 and RKO-I8. Stable Isotope Labeling by Amino Acids in Cell Culture technology was used to identify the differently expressed proteins, and the proteomics data were analyzed by ingenuity pathway analysis. PAK1-PBD immunoprecipitation combined with Western blot were carried out to determine Cdc42 activity, and qRT-PCR and Western blot were used to determine gene expression. The functional role of Cdc42BPA and Cdc42 pathway in colon cancer invasion was studied by loss-of-function experiments including pharmacological blockade, siRNA knockdown, chamber invasion, and WST-1 assays. Human colon cancer tissue microarray was analyzed by immunohistochemistry for overexpression of Cdc42BPA and its correlation with clinicopathological parameters and patient survival outcomes. HCT116-I8 and RKO-I8 cells showed significantly stronger invasive potential as well as decreased E-cadherin and increased vimentin expressions compared with parental cells. The differently expressed proteins in I8 cells compared with parental cells were identified. Bioinformatics analysis of proteomics data suggested that Cdc42BPA protein and Cdc42 signaling pathway are important for colon cancer invasion, which was confirmed by experimental data showing upregulation of Cdc42BPA and higher expression of active GTP-bound form of Cdc42 in HCT116-I8 and RKO-I8 cells. Functionally, pharmacological and genetic blockade of Cdc42BPA and Cdc42 signaling markedly suppressed colon cancer cell invasion and reversed epithelial mesenchymal transition process. Furthermore, compared with adjacent normal tissues, Cdc42BPA expression was significantly higher in colon cancer tissues and further upregulated in metastatic tumors in lymph nodes. More importantly, Cdc42BPA expression was correlated with metastasis and poor survival of the patients with colon cancer. This study provides the first evidence that Cdc42BPA and Cdc42 signaling are important for colon cancer invasion, and Cdc42BPA has potential implications for colon cancer prognosis and treatment.

The roles of microRNA-34b-5p in angiogenesis of thyroid carcinoma

PURPOSE

This study aims to determine the expression of miR-34b-5p in thyroid carcinomas and to investigate the role of miR34b-5p in the modulation of proteins involved in angiogenesis of thyroid carcinoma cells.

METHODS

The expressions of miR-34b-5p levels in five cell lines and 65 tissue samples from thyroid carcinomas were examined by real-time polymerase chain reaction. An exogenous miR-34b-5p (mimic) transiently overexpress miR-34b-5p in theses thyroid carcinoma cells. The effects of miR-34b-5p overexpression on the proteins involved in angiogenesis and cell cycle regulations (VEGF-A, Bcl-2 and Notch1) were investigated by Western blot, immunofluorescence, enzyme-linked immunosorbent assay followed by cell cycle analysis and apoptosis assays.

RESULTS

miR-34b-5p is markedly downregulated in all thyroid carcinoma cell lines and tissues samples when compared with non-neoplastic immortalised thyroid cell line and non-neoplastic thyroid tissues, respectively. The expression levels of miR-34b were significantly associated with T-stages of thyroid carcinomas (p = 0.042). Downregulation of VEGF-A, Bcl-2 and Notch1 proteins in thyroid carcinoma cells were noted in cells that transiently transfected with miR-34b-5p mimic. In addition, enzyme-linked immunosorbent assay confirmed the decreased expression of VEGF in thyroid carcinoma cells after transfection with miR-34b-5p mimic. Furthermore, miR-34b-5p mimic transfection induces significant accumulation of cells in G0-G1 of the cell cycle by blocking of their entry into the S transitional phase as well as increasing the total apoptosis.

CONCLUSIONS

miR-34b-5p functions as a potent regulator of angiogenesis, apoptosis and cell proliferation via modulation of VEGF-A, Bcl-2 and Notch1 proteins. It could be a target for developing treatment strategies of thyroid carcinoma with aggressive clinical behaviour.

MicroRNA-377 suppresses initiation and progression of esophageal cancer by inhibiting CD133 and VEGF

Esophageal cancer is one of the most lethal cancers worldwide with poor survival and limited therapeutic options. The discovery of microRNAs created a new milestone in cancer research. miR-377 is located in chromosome region 14q32, which is frequently deleted in esophageal squamous cell carcinoma (ESCC), but the biological functions, clinical significance and therapeutic implication of miR-377 in ESCC are largely unknown. In this study, we found that miR-377 expression was significantly downregulated in tumor tissue and serum of patients with ESCC. Both tumor tissue and serum miR-377 expression levels were positively correlated with patient survival. Higher serum miR-377 expression was inversely associated with pathologic tumor stage, distant metastasis, residual tumor status and chemoradiotherapy resistance. The roles of miR-377 in suppressing tumor initiation and progression, and the underlying molecular mechanisms were investigated. Results of in vitro and in vivo experiments showed that miR-377 overexpression inhibited the initiation, growth and angiogenesis of ESCC tumors as well as metastatic colonization of ESCC cells, whereas silencing of miR-377 had opposite effects. Mechanistically, miR-377 regulated CD133 and VEGF by directly binding to their 3' untranslated region. Moreover, systemic delivery of formulated miR-377 mimic not only suppressed tumor growth in nude mice but also blocked tumor angiogenesis and metastasis of ESCC cells to the lungs without overt toxicity to mice. Collectively, our study established that miR-377 plays a functional and significant role in suppressing tumor initiation and progression, and may represent a promising non-invasive diagnostic and prognostic biomarker and therapeutic strategy for patients with ESCC.

Pre-metastatic niches: organ-specific homes for metastases

It is well established that organs of future metastasis are not passive receivers of circulating tumour cells, but are instead selectively and actively modified by the primary tumour before metastatic spread has even occurred. Sowing the 'seeds' of metastasis requires the action of tumour-secreted factors and tumour-shed extracellular vesicles that enable the 'soil' at distant metastatic sites to encourage the outgrowth of incoming cancer cells. In this Review, we summarize the main processes and new mechanisms involved in the formation of the pre-metastatic niche.

Antagonist antibodies to vascular endothelial growth factor receptor 2 (VEGFR-2) as anti-angiogenic agents

Interaction of numerous signaling pathways in endothelial and mesangial cells results in exquisite control of the process of physiological angiogenesis, with a central role played by vascular endothelial growth factor receptor 2 (VEGFR-2) and its cognate ligands. However, deregulated angiogenesis participates in numerous pathological processes. Excessive activation of VEGFR-2 has been found to mediate tissue-damaging vascular changes as well as the induction of blood vessel expansion to support the growth of solid tumors. Consequently, therapeutic intervention aimed at inhibiting the VEGFR-2 pathway has become a mainstay of treatment in cancer and retinal diseases. In this review, we introduce the concepts of physiological and pathological angiogenesis, the crucial role played by the VEGFR-2 pathway in these processes, and the various inhibitors of its activity that have entered the clinical practice. We primarily focus on the development of ramucirumab, the antagonist monoclonal antibody (mAb) that inhibits VEGFR-2 and has recently been approved for use in patients with gastric, colorectal, and lung cancers. We examine in-depth the pre-clinical studies using DC101, the mAb to mouse VEGFR-2, which provided a conceptual foundation for the role of VEGFR-2 in physiological and pathological angiogenesis. Finally, we discuss further clinical development of ramucirumab and the future of targeting the VEGF pathway for the treatment of cancer.

Identification of Novel FAM134B (JK1) Mutations in Oesophageal Squamous Cell Carcinoma

Mutation of FAM134B (Family with Sequence Similarity 134, Member B) leading to loss of function of its encoded Golgi protein and has been reported induce apoptosis in neurological disorders. FAM134B mutation is still unexplored in cancer. Herein, we studied the DNA copy number variation and novel mutation sites of FAM134B in a large cohort of freshly collected oesophageal squamous cell carcinoma (ESCC) tissue samples. In ESCC tissues, 37% (38/102) showed increased FAM134B DNA copies whereas 35% (36/102) showed loss of FAM134B copies relative to matched non-cancer tissues. Novel mutations were detected in exons 4, 5, 7, 9 as well as introns 2, 4-8 of FAM134B via HRM (High-Resolution Melt) and Sanger sequencing analysis. Overall, thirty-seven FAM134B mutations were noted in which most (31/37) mutations were homozygous. FAM134B mutations were detected in all the cases with metastatic ESCC in the lymph node tested and in 14% (8/57) of the primary ESCC. Genetic alteration of FAM134B is a frequent event in the progression of ESCCs. These findings imply that mutation might be the major driving source of FAM134B genetic modulation in ESCCs.

Cancer-associated oxidoreductase ERO1-α drives the production of VEGF via oxidative protein folding and regulating the mRNA level

Background:

Endoplasmic reticulum disulfide oxidase 1-α (ERO1-α) is an oxidase that exists in the endoplasmic reticulum and has a role in the formation of disulfide bonds of secreted proteins and cell-surface proteins. Recently, we reported that ERO1-α is present in high levels in various types of tumours, and that ERO1-α is a novel factor of poor prognosis. However, how ERO1-α affects a tumour in vivo and why patients who have a tumour with a high expression level of ERO1-α have a poor prognosis are still unknown. Therefore, to clarify the mechanism, we investigated the effect of ERO1-α on a tumour from the point of view of angiogenesis.

Methods:

The effect of ERO1-α on tumour growth and angiogenesis was analysed by using non-obese diabetic-severe combined immunodeficient mice. The production of vascular endothelial growth factor (VEGF) in MDA-MB-231 cells with ERO1-α- overexpression or with ERO1-α knockdown was measured. The role of ERO1-α on VEGF expression was investigated. In triple-negative breast cancer cases, the relationship between expression of ERO1-α and angiogenesis was analysed.

Results:

We found that the expression of ERO1-α promoted tumour growth in a mouse study and angiogenesis. The effects of ERO1-α on angiogenesis were mediated via oxidative protein folding of VEGF and enhancement of VEGF mRNA expression by using MDA-MB-231. In triple-negative breast cancer cases, the expression of ERO1-α related to the number of the blood vessel. Furthermore, we found that ERO1-α was a poor prognosis factor in triple-negative breast cancer.

Conclusions:

Our study has established a novel link between expression of ERO1-α and secretion of VEGF, providing new evidence for the effectiveness of ERO1-α-targeted therapy in patients with ERO1-α-expressed cancer.

TNFAIP8 overexpression: a potential predictor of lymphatic metastatic recurrence in pN0 esophageal squamous cell carcinoma after Ivor Lewis esophagectomy

Esophageal squamous cell carcinoma (ESCC) has a poor prognosis due to high lymphatic metastatic recurrence rates after Ivor Lewis esophagectomy. We sought to investigate the correlation between tumor necrosis factor alpha-induced protein 8 (TNFAIP8) expression and postoperative lymphatic recurrence in patients with pN0 ESCC. One hundred twenty-two patients with pN0 ESCC undergoing Ivor Lewis esophagectomy were enrolled in this study. TNFAIP8 overexpression was found in 73 (59.8 %) tumor specimens. The 3-year lymphatic metastatic recurrence rate among TNFAIP8-overexpressing patients was significantly higher than in TNFAIP8-negative patients (p = 0.003). Multivariate Cox regression identified TNFAIP8 overexpression as an independent risk factor for lymphatic recurrence (p = 0.048). TNFAIP8 messenger RNA (mRNA) levels were significantly higher in patients with lymphatic recurrence than in patients without tumor recurrence (p = 0.019). Stable silencing of TNFAIP8 expression in ESCC-derived cells (Eca109) reduced proliferation, motility, and invasion and induced apoptosis. In addition, transient silencing of TNFAIP8 expression decreased cell motility and invasion and increased apoptosis in a second ESCC-derived cell line (KYSE150). Taken together, these findings suggest that TNFAIP8 overexpression is a potential biomarker to identify pN0 ESCC patients at higher risk of lymphatic recurrence who may benefit from adjuvant therapy.

Bone marrow-derived mesenchymal stem cell-secreted IL-8 promotes the angiogenesis and growth of colorectal cancer

Mesenchymal stem cells (MSCs) have recently been shown to home to tumors and contribute to the formation of the tumor-associated stroma. In addition, MSCs can secrete paracrine factors to facilitate tumor progression. However, the involvement of MSC-derived cytokines in colorectal cancer (CRC) angiogenesis and growth has not been clearly addressed. In this study, we report that interleukin-8 (IL-8) was the most highly upregulated pro-angiogenic factor in MSCs co-cultured with CRC cells and was expressed at substantially higher levels in MSCs than CRC cells. To evaluate the effect of MSC-derived IL-8 on CRC angiogenesis and growth, we used MSCs that expressed small hairpin (interfering) RNAs (shRNA) targeting IL-8 (shIL-8-MSCs). We found that MSC-secreted IL-8 promoted human umbilical vein endothelial cell (HUVEC) proliferation and migration, tube-formation ability and CRC cell proliferation. Additionally, in vivo studies showed that MSCs promoted tumor angiogenesis partially through IL-8. Taken together, these findings suggest that IL-8 secreted by MSCs promotes CRC angiogenesis and growth and can therefore serve as a potential novel therapeutic target.

Increasing demonstration of angiogenic markers in skin neoplastic lesions

BACKGROUND

Skin cancer represents the most common worldwide malignancy. Angiogenesis is an important factor in tumor growth and metastasis. Given these facts, the purpose of the current study was to compare the levels of angiogenic proteins in the context of the most common malignant and premalignant skin lesions.

METHODS

Immunohistochemistry of CD31, HIF1A, VEGFR1 and VEGFR2 was performed in basal cell carcinoma (BCC), actinic keratosis (AK) and squamous cell carcinoma of the skin (SCCS).

RESULTS

SCCS presented with increased levels of HIF1A, VEGFR1 and VEGFR2 in comparison to AK. In addition, SCCS also demonstrated increased levels of HIF1A to BCCLR or BCCHR. BCC presented with more vessels than AK. However, no correlation was observed among CD31, HIF1A, VEGFR1 and VEGFR2.

CONCLUSIONS

SCCS presented with higher levels of HIF1A, VEGFR1 and VEGFR2, while BCC demonstrated an increased number of vessels in relation to AK. These data suggest that antiangiogenic therapy might be useful for skin cancer treatment.

Modulatory role of miR-205 in angiogenesis and progression of thyroid cancer

miR-205 plays a crucial role in angiogenesis and has been found in association with several types of cancers. The aims of this study were to investigate the clinical and functional roles of miR-205 on as the major initiator and modulator of angiogenesis in thyroid cancer. 101 thyroid carcinomas, including 51 conventional and 37 follicular variants of papillary thyroid carcinomas, and 13 undifferentiated thyroid carcinomas in addition to 13 lymph nodes with metastatic thyroid carcinoma were recruited to be compared with 14 nodular goitre and seven normal thyroid tissues. Five thyroid carcinoma cell lines, of papillary and undifferentiated origin with and without history of metastasis, were also used. Expression of vascular endothelial growth factor A (VEGFA) and miR-205 were measured and exogenous miR-205 were transfected to observe the changes of VEGFA (by immunofluorescence and western blot techniques). Proliferation assay, cell cycle analysis and apoptosis assays were also used to evaluate the role of miR-205 in these events. Significant under-expression of miR-205 and over-expression of VEGFA mRNA and protein were noticed in thyroid cancer tissues and cell lines compared to normal thyroid control. Transfection of miR-205 into the cancer cell lines caused significant reduction of VEGFA protein and significant inhibition in cell proliferation, arrest in G0-G1 of the cell cycle and promotion of total apoptosis (P<0.05). The angiogenic and tumour-suppressive roles of miRNA-205 were demonstrated for the first time in thyroid cancer. The current experiments provided specific information on the functional consequences of VEGF manipulation via miRNA on cancer.

Preparation and functional characterization of human vascular endothelial growth factor-melittin fusion protein with analysis of the antitumor activity in vitro and in vivo

Vascular endothelial growth factor and its tyrosine kinase receptors have been identified as key mediators of the regulation of pathologic blood vessel growth and maintenance in the promotion of angiogenesis and tumor growth. Therefore, an alternative approach to destroying tumor endothelium would be to make this tissue particularly sensitive to VEGF-mediated drug delivery. To verify this hypothesis, we generated a protein containing VEGF165 fused to melittin. Melittin is a small linear peptide composed of 26 amino acid residues that can exert toxic or inhibitory effects on many types of tumor cells. This protein is a cytolytic peptide that attacks lipid membranes, leading to significant toxicity. In the present study, the Pichia pastoris expression system was used to express the fusion protein. Under optimal conditions, stable VEGF165-melittin production was achieved using a series of purification steps. The activity of VEGF165-melittin fusion protein was compared with melittin for its ability to suppress the growth of tumor cell line in vitro. The fusion toxin selectively inhibited growth of human hepatocellular carcinoma HepG-2 cell line with high expression of VEGFR-2. We found that sensitivity of VEGFR-2 transfected 293 cells to VEGF165-melittin enhanced as the cellular VEGFR-2 density increased. In an in vivo initial experiment, the fusion protein inhibited tumor growth in xenografts assays. Furthermore, successful expression and characterization of the fusion protein demonstrated its efficacy for use as a novel treatment strategy for cancer.