Prospero homeobox 1 mediates the progression of gastric cancer by inducing tumor cell proliferation and lymphangiogenesis

Multifaceted roles of lymphatic and blood endothelial cells in the tumor microenvironment of hepatocellular carcinoma: A comprehensive review

The tumor microenvironment is a complex network of cells, extracellular matrix, and signaling molecules that plays a critical role in tumor progression and metastasis. Lymphatic and blood vessels are major routes for solid tumor metastasis and essential parts of tumor drainage conduits. However, recent studies have shown that lymphatic endothelial cells (LECs) and blood endothelial cells (BECs) also play multifaceted roles in the tumor microenvironment beyond their structural functions, particularly in hepatocellular carcinoma (HCC). This comprehensive review summarizes the diverse roles played by LECs and BECs in HCC, including their involvement in angiogenesis, immune modulation, lymphangiogenesis, and metastasis. By providing a detailed account of the complex interplay between LECs, BECs, and tumor cells, this review aims to shed light on future research directions regarding the immune regulatory function of LECs and potential therapeutic targets for HCC.

Lymphangiogenesis in gastric cancer: function and mechanism

Increased lymphangiogenesis and lymph node (LN) metastasis are thought to be important steps in cancer metastasis, and are associated with patient's poor prognosis. There is increasing evidence that the lymphatic system may play a crucial role in regulating tumor immune response and limiting tumor metastasis, since tumor lymphangiogenesis is more prominent in tumor metastasis and diffusion. Lymphangiogenesis takes place in embryonic development, wound healing, and a variety of pathological conditions, including tumors. Tumor cells and tumor microenvironment cells generate growth factors (such as lymphangiogenesis factor VEGF-C/D), which can promote lymphangiogenesis, thereby inducing the metastasis and diffusion of tumor cells. Nevertheless, the current research on lymphangiogenesis in gastric cancer is relatively scattered and lacks a comprehensive understanding. Therefore, in this review, we aim to provide a detailed perspective on molecules and signal transduction pathways that regulate gastric cancer lymphogenesis, which may provide new insights for the diagnosis and treatment of cancer.

The significance of the microlymphangiogenesis, microangiogenesis, and combined detection of programmed cell death-1 protein (PD-1)/ki67 in gastric cancer tissues

PURPOSE

To investigate the relationship between the microlymphangiogenesis, microangiogenesis, and combined detection of the programmed cell death-1 protein (PD-1)/ki67 in patients with gastric cancer as well as the disease prognosis.

METHODS

Immunohistochemistry was used to detect the microlymphatic density (MLD) and microvessel density (MVD) in the central and peripheral zones in 92 cases of gastric cancer, along with the number of PD-1- and ki67-positive tumor cells.

RESULTS

The central zone of the gastric cancer tissue contained fewer atretic cord-like lymphatic vessels than the peripheral zone, while the peripheral zone contained an increased number of lymphatic vessels compared with the central zone. In most cases, the lumen was also dilated. Compared with the MLD in the peripheral zone, the MLD in central zone was significantly decreased. Compared with the number of PD-1-positive cells in the peripheral zone, the number of PD-1-positive cells in the central zone was significantly decreased, and compared with the number of ki67-positive cells in the peripheral zone. The differences in the microlymphangiogenesis, microangiogenesis, and the number of PD-1- and ki67-positive cells among the different histological types were not statistically significant. The microlymphangiogenesis, microangiogenesis, and PD-1- and ki67-positive cells were significantly decreased in the gastric cancer tissues from the patients in stages T1 and T2 compared with the gastric cancer tissues from the patients in stages T3 and T4.

CONCLUSIONS

The detection of the MLD and MVD as well as the positive expression of PD-1 and ki67 in gastric cancer tissue are important reference indicators for judging the prognosis of gastric cancer.

The Role of PROX1 in Neoplasia: A Key Player Often Overlooked

The human PROX1 gene (Prospero homeobox gene 1) is a member of the homeobox transcription factor family. PROX1 plays a key role in the development of the lymphatic system and is primarily used as a lymphatic vessel marker. However, as the accumulating evidence indicates that PROX1 is also implicated in the tumorigenesis of various cancer types, the scientific community has attempted to elucidate its complicated function in neoplasia pathogenesis, as well as its utility in cancer diagnosis, prognosis, and therapy. PROX1 has been shown to participate in the complex molecular mechanisms affecting tumorigenesis and has been associated with a plethora of clinicopathological parameters, including tumor stage and patients’ overall survival. Depending on the specific organ affected, PROX1 has exhibited both tumor-promoting and tumor-suppressing properties, with its inhibition and reactivation representing possible novel therapeutic interventions, respectively. Moreover, researchers have reported PROX1 as a useful tool in the fields of diagnosis and prognosis assessment. The current study aims to summarize and present the existing data that render PROX1 a novel and useful diagnostic and prognostic biomarker, as well as a possible therapeutic target.

Lack of relationship between PROX1 expression and clinicopathological parameters and prognosis in gastric cancer patients: a meta-analysis and TCGA analysis

Background

The relationship between PROX1 expression and clinicopathological characteristics and prognosis in patients with gastric cancer (GC) remain controversial. The aim of this study is to determine the clinicopathological and prognostic significance of PROX1 expression in patients with GC.

Methods

A systematic literature search and meta-analysis were performed. Odds ratio (OR) and confidence interval (CI) were used to evaluated the relationship between PROX1 expression and clinicopathological characteristics and overall survival (OS) of GC patients. Additionally, the Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) datasets were utilized to examine the relationship between PROX1 expression and clinicopathological significance and OS in GC patients.

Results

A total of 8 studies pooling 1289 GC patients were included in the assessment. In GC patients, PROX1 expression was not related to gender (OR: 1.234, 95% CI 0.958–1.590, P = 0.104), depth of tumor invasion (OR: 0.742, 95% CI 0.428–1.287, P = 0.289), lymph node metastasis (OR: 2.161, 95% CI 0.808–5.779, P = 0.125), TNM stage (OR: 1.324, 95% CI 0.572–3.066, P = 0.513), tumor size (OR: 0.889, 95% CI 0.502–1.576, P = 0.687), distant metastasis (OR: 1.096, 95% CI 0.470–2.555, P = 0.763). In addition, we also found that PROX1 expression was not associated with 1-year OS (OR: 0.908, 95% CI 0.631–1.306, P = 0.602), 3-year OS (OR: 1.234, 95% CI 0.482–3.160, P = 0.661) and 5-year OS (OR: 0.853, 95% CI 0.266–2.736, P = 0.790). According to TCGA, in comparison with high and low PROX1 expression in GC patients, the OS did not differ statistically (p = 0.119).

Conclusion

The expression of PROX1 was shown to lack a significant relationship to gender, TNM stage, depth of invasion, tumor size, stage, distant metastasis, or lymph node metastasis in statistically. The expression of PROX1 was not related to OS and it failed to be a meaningful biomarker to prevent and diagnose GC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02229-6.

Prognostic Impact of LGR5, Prox1, and Notch1 Biomarkers in Stage II to III Colon Cancer

The potentiation and activation of Wnt signaling pathways are now assumed to mediate the self-renewal and proliferation of colon cancer stem cells that are responsible for therapeutic resistance, tumor relapse, and metastasis. We aimed to evaluate LGR5, Prox1, and Notch1 immunohistochemical expression in stage II to III colon cancer. Their predictive role of tumor relapse, overall survival, and disease-free survival was statistically analyzed. Our results revealed that high LGR5 expression was identified in 56.7% of the patients, LGR5 expression was significantly associated with left-sided tumors (P<0.001). Moreover, its expression was significantly associated with the unfavorable tumor characteristics including high grade, deep invasion (pT), lymph node metastasis, and advanced tumor stage (P<0.001 for each). High Prox1 expression was observed in 65% of the cases, and its expression was significantly associated with tumor grade, lymph node metastasis, and the advanced tumor stage (P=0.004, 0.009, 0.016, respectively). Positive Notch1 expression was identified in 35% of patients, and it was inversely associated with high grade lymph node metastasis, deep invasion (pT), and advanced tumor stage (P<0.001 for each). During the follow-up period, the tumor relapse was significantly associated with high LGR5, high Prox1, and negative Notch1 expression. Shorter overall survival and disease-free survival were significantly associated with high LGR5, high Prox1, and negative Notch1 expression. High LGR5, high Prox1, and negative Notch1 expression are unfavorable prognostic factors in colon cancer. Prox1 is a crucial regulator of Notch-independent LGR5+ stem cells that is mostly responsible for relapse and therapeutic resistance in stage II to III colon cancer.

β-catenin plus PROX1 immunostaining stratifies disease progression and patient survival in neoadjuvant-treated pancreatic cancer

BACKGROUND

Wnt/β-catenin signaling is a highly conserved signaling pathway that regulates the transcription factor PROX1. The role of β-catenin and PROX1 in pancreatic cancer is ambiguous, as some studies have associated their expression with tumor regression and some with tumor progression.

OBJECTIVE

We have investigated their expression in surgically treated pancreatic cancer patients receiving neoadjuvant therapy (NAT), and patients treated upfront with surgery (US). We furthermore compared the expression of β-catenin and PROX1 between patients who had a good or poor response to NAT.

METHODS

We evaluated β-catenin and PROX1 expression through immunohistochemistry in 88 neoadjuvant and 144 upfront surgery patients by scoring the intensity of the immunopositivity as 0-3, corresponding to negative, weak, moderate, or strong. We developed a six-tier grading scheme for the neoadjuvant responses by analyzing the remaining tumor cells in surgical specimen histological sections.

RESULTS

Strong β-catenin immunopositivity associated with improved survival in the patients with good NAT-response (≤10% residual tumor cells) (Hazard ratio [HR] 0.26 95%, confidence interval [CI] 0.07-0.88 p = 0.030). Additionally, the combined moderate β-catenin and PROX1 expression associated with improved survival (HR 0.20 95% CI 0.05-0-76 p = 0.018) among the good responders. Among the patients with a poor NAT-response (> 10% residual tumor cells), both strong β-catenin immunopositivity and strong combined β-catenin and PROX1 associated with shorter survival (HR 2.03 95% CI 1.16-3.55 p = 0.013, and HR 3.1 95% CI 1.08-8.94 p = 0.03, respectively). PROX1 alone was not associated with survival.

CONCLUSIONS

Strong β-catenin immunopositivity and combined strong or moderate β-catenin and PROX1 immunopositivity associated with improved survival among the good NAT-responders and worse survival among the poor NAT-responders.

Clinico-pathological and prognostic implications of Srx, Nrf2, and PROX1 expression in gastric cancer and adjacent non-neoplastic mucosa - an immunohistochemical study

Introduction

Sulfiredoxin (Srx), which is an endogenous antioxidant substance which could, regulate the signaling pathways of reactive oxygen species. Nuclear factor erythroid 2-related factor 2 (Nrf2) is Cap-N-collar (CNC) transcription factors family member that have essential roles in regulation of antioxidant response. The transcription factor PROX1 is a transcription factor and a key regulatory protein in cancer development.

Aim of the study

To analyze levels of tissue expression of Srx, Nrf2, and PROX1 in gastric cancer and adjacent non-neoplastic gastric mucosa to clarify the relationship between their expression levels, clinical, pathological parameters and patients’ outcome. The results might lead to discovering novel targeted therapies to gastric cancers.

Material and methods

We included 70 paraffin-embedded samples: 50 specimens from gastric carcinomas and 20 specimens from adjacent non-neoplastic gastric mucosa. All samples are stained with Srx, Nrf2, and PROX1 using immunohistochemistry, correlated their expression with clinicopathological and prognostic parameters of patients.

Results

High levels of Srx and Nrf2 expression were positively associated with higher cancer grade (p = 0.006, 0.031 respectively), advanced stage (p < 0.001, 0.02 respectively), higher incidence of distant metastases (p = 0.029, 0.03 respectively) and dismal outcome (p < 0.001). High levels of PROX1 expression were associated with lower cancer grade (p = 0.005), absence of lymph nodes metastases (p = 0.023), early stage (p = 0.003), absence of relapse (p = 0.004), and favorable outcome (p < 0.001).

Conclusions

Srx and Nrf2 expression increase gastric cancer invasiveness, suggesting their utility as poor prognostic markers, but PROX1 serves as a favorable prognostic marker of gastric cancer patients.

Exosomal long noncoding RNA LNMAT2 promotes lymphatic metastasis in bladder cancer

Patients with bladder cancer (BCa) with clinical lymph node (LN) metastasis have an extremely poor prognosis. VEGF-C has been demonstrated to play vital roles in LN metastasis in BCa. However, approximately 20% of BCa with LN metastasis exhibits low VEGF-C expression, suggesting a VEGF-C-independent mechanism for LN metastasis of BCa. Herein, we demonstrate that BCa cell-secreted exosome-mediated lymphangiogenesis promoted LN metastasis in BCa in a VEGF-C-independent manner. We identified an exosomal long noncoding RNA (lncRNA), termed lymph node metastasis-associated transcript 2 (LNMAT2), that stimulated human lymphatic endothelial cell (HLEC) tube formation and migration in vitro and enhanced tumor lymphangiogenesis and LN metastasis in vivo. Mechanistically, LNMAT2 was loaded to BCa cell-secreted exosomes by directly interacting with heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1). Subsequently, exosomal LNMAT2 was internalized by HLECs and epigenetically upregulated prospero homeobox 1 (PROX1) expression by recruitment of hnRNPA2B1 and increasing the H3K4 trimethylation level in the PROX1 promoter, ultimately resulting in lymphangiogenesis and lymphatic metastasis. Therefore, our findings highlight a VEGF-C-independent mechanism of exosomal lncRNA-mediated LN metastasis and identify LNMAT2 as a therapeutic target for LN metastasis in BCa.

RPL38 Regulates the Proliferation and Apoptosis of Gastric Cancer via miR-374b-5p/VEGF Signal Pathway

Aim

To explore the role of RPL38 on proliferation and apoptosis of gastric cancer cells by regulating miR-374b-5p/VEGF signal pathway.

Methods

qRT-PCR was used to measure the expression of RPL38. CCK8 assay, Matrigel invasion assay, and flow cytometry were used to detect the role of RPL38in MKN-45 cells. Western blot was used to measure the protein expression of VEGF, p-ERK, ERK, p-AKT, AKT in cells. Dual-luciferase assay was performed to verify the relationship between miR-374b-5p and RPL38, miR-374b-5p and VEGF.

Results

In our research, we found that RPL38 was upregulation in gastric cancer, loss function of RPL38 could inhibit MKN-45 cell proliferation and invasion, accompany with increasing apoptosis. Then, we verified that RPL38 could interact with miR-374b-5p by performed luciferase assay, there was a negative correlation between RPL38 and miR-374b-5p. Furthermore, we observed that VEGF is a potential target of miR-374b-5p, miR-374b-5p negatively regulated the expression of VEGF, and effected ERK/AKT signal pathways. Next, we found that miR-374b-5p inhibitor or overexpression of VEGF could prevent the anti-tumor function of si-RPL38.

Conclusion

Knockdown of RPL38 inhibits the proliferation and apoptosis of gastric cancer via miR-374b-5p/VEGF signal pathway.

Nervous system and gastric cancer

The nervous system has been recently shown to exert impact on gastric cancer directly and indirectly. Gastric cancer cells invade nerve fibers to induce outgrowth and branching of neural cells, and nerve fibers in turn infiltrate into tumor microenvironment to promote progression of gastric cancer. Additionally, the neuro-immune interaction also plays an important role in gastric cancer development. The interplay of nerves and gastric cancer is mediated by many nervous system-associated factors, which can not only be synthesized and released by both cancer cells and nerve terminals, but also participate in regulation of many aspects of gastric cancer such as cell proliferation, angiogenesis, metastasis and recurrence. Furthermore, clinical researches indicate that some of these factors are significant diagnosis and prognosis biomarkers for gastric cancer. Herein, we reviewed recent advances and future prospects of the interaction between nervous system and gastric cancer.

A novel role of HIF-1α/PROX-1/LYVE-1 axis on tissue regeneration after renal ischaemia/reperfusion in mice

Context: Renal ischaemia reperfusion (I/R) is a common clinical condition with a high morbidity and mortality rate. To date, I/R-induced renal injury remains an ineffective treatment. Objective: We hypothesis that angiogenesis and lymphangiogenesis markers, prospero homeobox-1 (PROX-1) and lymphatic endothelial hyaluronan receptor-1 (LYVE-1), are critical during I/R. Material and methods: Kunming mice were subjected to I/R and observed for the following eight consecutive days. Pathology analysis and protein distribution were detected by H&E staining, immunohistochemistry and immunofluorescence confocal analysis. Results: After I/R treatment, renal pathology was changed. HIF-1α was induced in the early stage and colocalisation with PROX-1 mainly in the renal tubular region, whereas PROX-1 and LYVE-1 were colocalised in the glomerulus of the endothelial region. Conclusions: In this study, we revealed HIF-1α/PROX-1/LVYE-1 axis dynamic changes in different regions after I/R and demonstrated for the first time it activates during I/R repair.

High tissue MMP14 expression predicts worse survival in gastric cancer, particularly with a low PROX1

Matrix metalloproteinase 14 (MMP14), a membrane-associated matrix metalloproteinase, has been shown to influence the invasion and metastasis of several solid tumors. Prospero homeobox protein 1 (PROX1), involved in the development and cell fate determination, is also expressed in malignant diseases functioning either as a tumor-suppressing or oncogenic factor. In certain cancers PROX1 appears to transcriptionally suppress MMP14 expression. This study, therefore, aimed to explore the association between MMP14 and PROX1 and understand their potential as prognostic biomarkers in gastric cancer. The cohort consisted of 313 individuals operated for gastric adenocarcinoma between 2000 and 2009 in the Department of Surgery, Helsinki University Hospital. MMP14 and PROX1 expressions were studied using immunohistochemistry in the patient sample and using immunoblotting and immunofluorescence in gastric cancer cell lines. We generated survival curves using the Kaplan-Meier method, determining significance via the log-rank test. A high MMP14 expression associated with being ≥67 years (P = .041), while a positive nuclear PROX1 expression associated with tumors of a diffuse histological type (P = .041) and a high cytoplasmic PROX1 expression (P < .001). Five-year disease-specific survival among patients with a high MMP14 expression was 35.9% (95% confidence interval [CI] 24.9-46.9), compared to 45.3% (95% CI 38.0-52.6) for patients with a low MMP14 (P = .030). Survival was worse specifically among those with a high MMP14 and absent nuclear PROX1 expression (hazard ratio [HR] 1.65; 95% CI 1.09-2.51; P = .019). Thus, this study confirms that a high MMP14 expression predicts a worse survival in gastric cancer, revealing for the first time that survival is particularly worse when PROX1 is low.

Molecular Signature of Prospero Homeobox 1 (PROX1) in Follicular Thyroid Carcinoma Cells

The prospero homeobox 1 (PROX1) transcription factor is a product of one of the lymphangiogenesis master genes. It has also been suggested to play a role in carcinogenesis, although its precise role in tumour development and metastasis remains unclear. The aim of this study was to gain more knowledge on the PROX1 function in thyroid tumorigenesis. Follicular thyroid cancer-derived cells—CGTH-W-1—were transfected with PROX1-siRNA (small interfering RNA) and their proliferation, cell cycle, apoptosis and motility were then analysed. The transcriptional signature of PROX1 depletion was determined using RNA-Sequencing (RNA-Seq) and the expression of relevant genes was further validated using reverse transcriptase quantitative PCR (RT-qPCR), Western blot and immunocytochemistry. PROX1 depletion resulted in a decreased cell motility, with both migratory and invasive potential being significantly reduced. The cell morphology was also affected, while the other studied cancer-related cell characteristics were not significantly altered. RNA-seq analysis revealed significant changes in the expression of transcripts encoding genes involved in both motility and cytoskeleton organization. Our transcriptional analysis of PROX1-depleted follicular thyroid carcinoma cells followed by functional and phenotypical analyses provide, for the first time, evidence that PROX1 plays an important role in the metastasis of thyroid cancer cells by regulating genes involved in focal adhesion and cytoskeleton organization in tumour cells.

Hallmarks of Cancer-Related Newly Prognostic Factors of Oral Squamous Cell Carcinoma

Head and neck cancer, including oral squamous cell carcinoma (OSCC), is the sixth leading malignancy worldwide. OSCC is an aggressive tumor and its prognosis has exhibited little improvement in the last three decades. Comprehensive elucidation of OSCC's molecular mechanism is imperative for early detection and treatment, improving patient survival. Based on broadly accepted notions, OSCC arises from multiple genetic alterations caused by chronic exposure to carcinogens. In 2011, research revealed 10 key alterations fundamental to cancer cell development: sustaining proliferative signaling, evading growth suppressors, avoiding immune destruction, activating invasion and metastasis, tumor-promoting inflammation, enabling replicative immortality, inducing angiogenesis, genome instability and mutation, resisting cell death, and deregulating energetics. This review describes molecular pathological findings on conventional and novel hallmarks of OSCC prognostic factors. In addition, the review summarizes the functions and roles of several molecules as novel OSCC prognosticators.

Review of recent efforts to discover biomarkers for early detection, monitoring, prognosis, and prediction of treatment responses of patients with gastric cancer

Gastric cancer (GC) is the leading cause of cancer-related death worldwide. Despite recent advances in diagnosis and therapy, the prognosis of patients with GC is poor. Many patients have inoperable disease upon diagnosis or experience recurrent disease after curative gastrectomy. Unfortunately, tumor markers for GC, such as serum carcinoembryonic antigen and carbohydrate antigen 19-9, lack sufficient sensitivity and specificity. Therefore, effective biomarkers are required to detect early GC and to predict tumor recurrence and chemosensitivity. Areas covered: Here we aimed to review recent developments in techniques that improve the detection of aberrant expression of GC-associated molecules, including protein coding genes, microRNAs, long noncoding RNAs, and methylated promoter DNAs. Expert commentary: Detection of genetic and epigenetic alterations in gastric tissue or in the circulation will likely improve the diagnosis and management of GC to achieve significantly improved outcomes.

Disodium Cromolyn and Anti-podoplanin Antibodies Strongly Inhibit Growth of BHK 21/C13-derived Fibrosarcoma in a Chick Embryo Chorioallantoic Membrane Model

AIM

To characterize baby hamster kidney fibroblast (BHK 21/C13) cells and test the effects of antibodies against podoplanin and disodium cromolyn on BHK 21/C13 cell line-derived tumors grown on chick embryo chorioallantoic membrane (CAM).

MATERIAL AND METHODS

BHK 21/C13 cell-derived fibrosarcomas developed in hamsters were implanted on CAM and treated with anti-podoplanin antibodies and disodium cromolyn. BHK 21/C13 cell immunophenotype was assessed.

RESULTS

Fibrosarcoma cells were positive for vimentin, CD117, smooth muscle actin, vascular endothelial growth factor epidermal growth factor receptor, homebox prospero gene 1 and negative for platelet-derived growth factor B, neuron-specific enolase, S100, CD34, Ewing sarcoma and podoplanin. CAM-grown fibrosarcomas were highly sensitive to disodium cromolyn and anti-podoplanin antibodies.

CONCLUSION

Immunophenotyping BHK 21/C13 cells and their response to drugs represent the first step in revealing cell line utility and a reliable tool for experimental cancer research.

High Expression of Prospero-Related Homeobox-1 (PROX1) Is Associated With Poor Prognosis in Patients With Salivary Adenoid Cystic Carcinoma

PURPOSE

Prospero-related homeobox-1 (PROX1) plays an important role in the invasion and metastasis of many human cancers. However, the expression pattern of PROX1 in salivary adenoid cystic carcinoma (SACC) remains unclear. The aim of this study was to investigate PROX1 expression and its prognostic value in SACC.

MATERIALS AND METHODS

PROX1 expression was determined by immunohistochemistry (IHC) in SACC tissue specimens. Correlations between PROX1 expression and clinicopathologic features were investigated. The Kaplan-Meier method was used to analyze the correlation between PROX1 expression and survival. Independent prognostic factors associated with overall survival (OS) were analyzed using Cox regression analysis.

RESULTS

The IHC data showed that the PROX1 positivity rate in SACC tissue specimens was significantly higher than that in normal salivary gland tissues (71.1 vs 13.3%; P < .05). PROX1 expression was detected mainly in the nucleolus. In addition, PROX1 expression was correlated with perineural invasion, local regional recurrence, and distant metastasis of patients with SACC (P < .05), and no significant association was found between PROX1 expression and other clinicopathologic parameters. Data indicated that patients with positive PROX1 expression had poor OS compared with those with negative PROX1 expression (P = .0005). Multivariate analysis showed that PROX1 expression, local regional recurrence, and distant metastasis were independent prognostic factors for OS.

CONCLUSIONS

These findings showed that PROX1 expression was statistically higher in SACC specimens. Positive expression of PROX1 might serve as a potential predictor of prognosis in SACC.

A meta-analysis of the lymphatic microvessel density and survival in gastric cancer with 1809 cases

Lymph node metastasis commonly occurs in gastric cancer. Previous studies have demonstrated that the overexpression of lymphatic microvessel density (LVD) is correlated with various malignancies. To evaluate the potential role of LVD in various malignancies, we conducted a systematic review and meta-analysis to thoroughly investigate the association of LVD expression with tumor progression and survival in gastric cancer. We performed a comprehensive search of common databases and selected studies demonstrating the relationship between LVD expression and gastric cancer prognosis. Hazard ratios (HR) were used to determine the value of LVD for predicting gastric cancer metastasis and prognosis. The data were extracted from the included studies and pooled with the appropriate effects model using STATA 12.0. The results showed that high LVD expression obviously impacted the prognosis of gastric cancer, based on an overall survival (OS) HR of 2.58 (95% CI: 1.91–3.48, P < 0.001) and a disease-free survival (DFS) HR of 2.51 (95% CI: 1.35–4.68, P = 0.004) in the univariate analysis. In addition, the results of the multivariate analysis indicated a remarkable relationship between high LVD expression and gastric neoplasm prognosis. The pooled OS HR was 4.12 (95% CI: 3.45–4.91, P < 0.001). The current meta-analysis shows that high LVD is closely related to tumor metastasis and poor prognosis in gastric malignancy. LVD could be a key factor in tumor lymphatic metastasis. Moreover, LVD is likely a potential index and an effective biomarker for the prediction of patient prognosis.

miR-27a induced by colon cancer cells in HLECs promotes lymphangiogenesis by targeting SMAD4

Aim

Metastasis of tumor cells occurs through lymphatic vessels, blood vessels and transcoelomic spreading. Growing evidence from in vivo and in vitro studies has indicated that tumor lymphangiogenesis facilitates metastasis. However, the regulation of lymphangiogenesis in colon cancer remains unclear. The aims of this study were to identify key miRNAs in colon cancer lymphangiogenesis and to investigate its target and mechanism.

Methods

miRNA microarray analysis was conducted to identify miRNAs in human lymphatic endothelial cells (HLECs) that were regulated by co-cultured human colon cancer cells. Gain- and loss-of-function studies were performed to determine the function of miR-27a, a top hint, on lymphangiogenesis and migration in HLECs. Furthermore, bioinformatics prediction and experimental validation were performed to identify miR-27a target genes in lymphangiogenesis.

Results

We found that expression of miR-27a in HLECs was induced by co-culturing with colon cancer cells. Over-expression of miR-27a in HLECs enhanced lymphatic tube formation and migration, whereas inhibition of miR-27a reduced lymphatic tube formation and migration. Luciferase reporter assays showed that miR-27a directly targeted SMAD4, a pivotal component of the TGF-β pathway. In addition, gain-of-function and loss-of-function experiments showed that SMAD4 negatively regulated the length of lymphatic vessels formed by HLECs and migration.

Conclusions

Our data indicated that colon cancer cell induced the expression of miR-27a in HLECs, which promoted lymphangiogenesis by targeting SMAD4. Our finding implicated miR-27a as a potential target for new anticancer therapies in colon cancer.

High PROX1 expression in gastric cancer predicts better survival

BACKGROUND

PROX1 is a transcription factor involved in the development of various organs. It has also an important function in colorectal cancer progression. The aim of this study was to investigate the prognostic role of PROX1 expression in gastric cancer.

METHODS

We evaluated PROX1 expression in gastric cancer by immunohistochemistry of tumor-tissue microarrays including tumor specimens from 283 patients who underwent surgery at Helsinki University Hospital. We investigated the association of PROX1 expression with clinicopathologic variables and patient survival.

RESULTS

Cytoplasmic PROX1 reactivity was high in 56 (20.5%) and low in 217 (79.5%) cases. Low PROX1 immunostaining associated with diffuse cancer type (p = 0.002). In subgroup analysis, PROX1 was a significant marker of better prognosis in patients aged under 66 (p = 0.007), in those with intestinal cancer (p = 0.025), among men (p = 0.019), and in tumors of less than 5 cm diameter (p = 0.030). Patients with high PROX1 expression had a cancer-specific 5-year survival of 65.6% (95% CI 52.7-78.5), compared to 37.1% (95% CI 30.2-44.0) for those with low expression (p = 0.004, log-rank test). This result remained significant in multivariable analysis (HR = 0.56; 95% CI 0.35-0.90; p = 0.017).

CONCLUSION

In gastric cancer, high cytoplasmic PROX1 expression is an independent marker of better prognosis.

Arctii Fructus Inhibits Colorectal Cancer Cell Proliferation and MMPs Mediated Invasion via AMPK

Although Arctii Fructus (AF) has been shown to have various pharmacological effects, there have been no studies concerning the inhibitory effects of AF on the metastatic properties of colorectal cancer (CRC). The aim of this study was to investigate whether AF could suppress CRC progression by inhibiting cell growth, epithelial-mesenchymal transition (EMT), migration, and the invasion ability of CRC cells. AF decreased proliferation of CRC cells by inducing cell cycle arrest and apoptosis via extrinsic and intrinsic apoptotic pathways. Regarding metastatic properties, AF inhibited EMT by increasing the expression of the epithelial marker, E-cadherin, and decreasing the expression of the mesenchymal marker, N-cadherin, in CT26 cells. Moreover, AF decreased the migration and invasion of CT26 cells by inhibiting matrix metalloproteinase-2 (MMP-2) and MMP-9 activity. We confirmed that the decreased invasion ability and MMP-9 activity by AF treatment involved AMP-activated protein kinase (AMPK) activation. Collectively, this study demonstrates that AF inhibits the proliferation and metastatic properties of CRC cells.

Prognostic significance of glutathione peroxidase 2 in gastric carcinoma

Increasing evidence suggests that the glutathione peroxidase 2 may actually play important roles in tumorigenesis and progression in various human cancers such as colorectal carcinomas and lung adenocarcinomas. However, the role of glutathione peroxidase 2 in gastric carcinoma remains to be determined. In this study, the expression and prognostic significance of glutathione peroxidase 2 in gastric carcinoma were investigated and the well-known prognostic factor Ki-67 labeling index was also assessed as positive control. Glutathione peroxidase 2 expression levels in the tumor tissue specimens, the matched adjacent normal tissue specimens, and the lymph node metastases of 176 patients with gastric carcinoma were evaluated by quantitative polymerase chain reaction, western blotting, and immunohistochemical staining. The associations between glutathione peroxidase 2 expression levels, as determined by immunohistochemical staining, and multiple clinicopathological characteristics were determined by Pearson's chi-square test and Spearman's correlation analysis. The relationships between glutathione peroxidase 2 expression and other clinicopathological variables and patient prognoses were analyzed further by the Kaplan-Meier method, the log-rank test, and Cox multivariate regression. The quantitative polymerase chain reaction, western blotting, and immunohistochemical staining results showed that glutathione peroxidase 2 expression levels were upregulated in both the primary tumor foci and the lymph node metastases of patients with gastric carcinoma (all p values < 0.05). Furthermore, Pearson's chi-square tests, as well as Spearman's correlation analysis, revealed that glutathione peroxidase 2 expression levels were strongly correlated with the Ki-67 labeling index, differentiation, histological patterns, Lauren classifications, lymph node metastasis, vascular invasion, tumor-node-metastasis stages, Helicobacter pylori infection, and overall survival (all p values < 0.05). Kaplan-Meier analysis, as well as the log-rank test and multivariate Cox regression analysis, showed that multiple clinicopathological risk factors and glutathione peroxidase 2 expression were novel independent prognostic factors for gastric carcinoma (all p values < 0.05). Glutathione peroxidase 2 expression is a novel independent prognostic biomarker for gastric carcinoma that may be used to devise personalized therapeutic regimens and precision treatments for this disease.

Impact of homeobox genes in gastrointestinal cancer

Homeobox genes, including HOX and non-HOX genes, have been identified to be expressed aberrantly in solid tumors. In gastrointestinal (GI) cancers, most studies have focused on the function of non-HOX genes including caudal-related homeobox transcription factor 1 (CDX1) and CDX2. CDX2 is a crucial factor in the development of pre-cancerous lesions such as Barrett’s esophagus or intestinal metaplasia in the stomach, and its tumor suppressive role has been investigated in colorectal cancers. Recently, several HOX genes were reported to have specific roles in GI cancers; for example, HOXA13 in esophageal squamous cell cancer and HOXB7 in stomach and colorectal cancers. HOXD10 is upregulated in colorectal cancer while it is silenced epigenetically in gastric cancer. Thus, it is essential to examine the differential expression pattern of various homeobox genes in specific tumor types or cell lineages, and understand their underlying mechanisms. In this review, we summarize the available research on homeobox genes and present their potential value for the prediction of prognosis in GI cancers.

PROX1 and β-catenin are prognostic markers in pancreatic ductal adenocarcinoma

Background

The Wnt/β-catenin pathway has a key role in regulating cellular processes and its aberrant signaling can lead to cancer development. The role of β-catenin expression in pancreatic ductal adenocarcinoma is somewhat controversial. Transcription factor PROX1 is a target of Wnt/β-catenin signaling and it is involved in carcinogenesis through alterations in its expression. The actions can be either oncogenic or tumor suppressive depending on the tissue. The aim of this study was to investigate PROX1 and β-catenin expression in pancreatic ductal adenocarcinoma (PDAC).

Methods

Expression of PROX1 and β-catenin were evaluated in 156 patients by immunohistochemistry of tissue microarrays. Associations between tumor marker expression and clinicopathological parameters were assessed by the Fischer’s exact-test or the linear-by-linear association test. The Kaplan-Meier method and log-rank test were used for survival analysis. Uni- and multivariate survival analyses were carried out by the Cox regression proportional hazard model.

Results

High PROX1 expression was seen in 74 (48 %) tumors, and high β-catenin expression in 100 (65 %). High β-catenin expression was associated with lower tumor grade (p = 0.025). High PROX1 and β-catenin expression associated significantly with lower risk of death from PDAC in multivariate analysis (HR = 0.63; 95 % CI 0.42–0.95, p = 0.026; and HR = 0.54; 95 % CI 0.35–0.82, p = 0.004; respectively). The combined high expression of PROX1 and β-catenin also predicted lower risk of death from PDAC (HR = 0.46; 95 % CI 0.28–0.76, p = 0.002).

Conclusion

In conclusion, high PROX1 and β-catenin expression were independent factors for better prognosis in pancreatic ductal adenocarcinoma.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2497-5) contains supplementary material, which is available to authorized users.