Mechanism of SEMA3B gene silencing and clinical significance in glioma

SEMA3B-AS1 suppresses colorectal carcinoma progression by inhibiting Semaphorin 3B-dependent VEGF signaling pathway activation

Mounting evidence has demonstrated the considerable regulatory effects of long noncoding RNAs (lncRNAs) in the tumorigenesis and progression of various carcinomas. LncRNA Semaphorin 3B (SEMA3B) antisense RNA 1 (SEMA3B-AS1) has been found to be dysregulated in a few carcinomas recently. However, its potential function and mechanism in colorectal carcinoma (CRC) have not yet been examined. Here we show that SEMA3B-AS1 acts as a crucial regulator of CRC progression. We found that SEMA3B-AS1 expression was downregulated in CRC cell lines and tissues. Downregulation of SEMA3B-AS1 was significantly associated with poor survival in CRC patients. Overexpression of SEMA3B-AS1 reduced the cell growth and metastasis of CRC in vivo and in vitro. In addition, SEMA3B-AS1 promoted the expression of its sense-cognate gene SEMA3B, a member of the Semaphorin family (SEMAs), by recruiting EP300 to induce H3K9 acetylation at the SEMA3B promoter. Furthermore, we proved that SEMA3B-AS1 suppressed CRC angiogenesis by affecting the vascular endothelial growth factor signaling pathway activation which was regulated by the SEMA3B-NRP1 axis. Our work unravels a novel mechanism of SEMA3B-AS1 in the inhibition of CRC malignant progression and highlights its probability as a new promising diagnostic marker and therapeutic target for CRC interventions.

Emerging roles and mechanisms of semaphorins activity in cancer

Semaphorins are regulatory molecules that are linked to the modulation of several cancer processes, such as angiogenesis, cancer cell invasiveness and metastasis, tumor growth, as well as cancer cell survival. Semaphorin (SEMA) activity depends on the cancer histotypes and their particularities. In broad terms, the effects of SEMAs result from their interaction with specific receptors/co-receptors - Plexins, Neuropilins and Integrins - and the subsequent effects upon the downstream effectors (e.g. PI3K/AKT, MAPK/ERK). The present article serves as an integrative review work, discussing the broad implications of semaphorins in cancer, focusing on cell proliferation/survival, angiogenesis, invasion, metastasis, stemness, and chemo-resistance/response whilst highlighting their heterogeneity as a family. Herein, we emphasized that semaphorins are largely implicated in cancer progression, interacting with the tumor microenvironment components. Whilst some SEMAs (e.g. SEMA3A, SEMA3B) function widely as tumor suppressors, others (e.g. SEMA3C) act as pro-tumor semaphorins. The differences observed in terms of the biological structure of SEMAs and the particularities of each cancer histotypes require that each semaphorin be viewed as a unique entity, and its roles must be researched accordingly. A more in-depth and comprehensive view of the molecular mechanisms that promote and sustain the malignant behavior of cancer cells is of utmost importance.

High STK40 Expression as an Independent Prognostic Biomarker and Correlated with Immune Infiltrates in Low-Grade Gliomas

Background

Expression of STK40 is observed in some cancer types, while its role in low-grade gliomas (LGG) is unclear. The present study aimed to demonstrate the relationship between STK40 and LGG based on The Cancer Genome Atlas (TCGA) database and bioinformatics analysis.

Methods

Kruskal-Wallis test, Wilcoxon sign-rank test, and logistic regression were used to evaluate the relationship between clinicopathological features and STK40 expression. Kaplan-Meier method and Cox regression analysis were used to evaluate prognostic factors. Gene set enrichment analysis (GSEA) and immuno-infiltration analysis were used to determine the significant involvement of STK40 in function.

Results

High STK40 expression in LGG was associated with WHO grade (P<0.001), IDH status (P<0.001), primary therapy outcome (P=0.027), 1p/19q codeletion (P<0.001) and histological type (P<0.001). High STK40 expression predicted a poorer overall survival (OS) (HR: 3.07; 95% CI: 2.09-4.51; P<0.001), progression-free survival (PFS) (HR:2.11; 95% CI: 1.59-2.81; P<0.001) and disease specific survival (DSS) (HR: 3.27; 95% CI: 2.17-4.92; P<0.001). STK40 expression (HR: 2.284; 95% CI: 1.125-4.637; P=0.022) was independently correlated with OS in LGG patients. GSEA demonstrated that pathways including cell cycle mitotic, neutrophil degranulation, signaling by Rho GTPases, signaling by interleukins, M phase, PI3K-Akt signaling pathway and naba secreted factors were differentially enriched in STK40 high expression phenotype. Immune infiltration analysis showed that STK40 expression was correlated with some types of immune infiltrating cells.

Conclusion

STK40 expression was significantly correlated with poor survival and immune infiltration in LGG, and it may be a promising prognostic biomarker in LGG.

Cisplatin Changes Expression of SEMA3B in Endometrial Cancer

BACKGROUND

Semaphorin 3B (SEMA3B) is characterized as a strong suppressing factor of the proliferation of cancerous cells and also by its anti-angiogenic effect. However, the knowledge on the changes in the expression profile of SEMA3B under the influence of cisplatin in endometrial cancer remains fragmented. The aim of this work was to note the changes in expression of SEMA3B when under the influence of cisplatin in the endometrial cancer cell line.

METHODS

Ishikawa cell line cells were exposed to three different concentrations of cisplatin: 2.5μM; 5μM; 10μM for 12, 24 and 48 hours and were compared to cells untreated by the drug. Changes in the expression profile of SEMA3B were determined based upon RtqPCR (mRNA) alongside the ELISA assay (protein). The Statistica 13.0 PL program was used for statistical analysis (p<0.05).

RESULTS

Changes on the transcriptome level seem to be more dynamic than on the proteome level. Regardless of the concentration given or the exposition period, the expression of semaphorin 3B was, in fact, higher in cells exposed to cisplatin. Statistically substantial differences (p<0.05) in the expression of SEMA3B mRNA and protein were seen for all incubation periods at the given cisplatin level when compared to the control.

CONCLUSION

Cisplatin causes a growth in the expression of SEMA3B in an endometrial cancer cell culture, this results in the restoration in the state of cell homeostasis and shows the effectiveness of pharmacotherapy, including a low risk of drug resistance.

Regulatory effects of Lactobacillus plantarum HY7714 on skin health by improving intestinal condition

Despite increasing research on the gut-skin axis, there is a lack of comprehensive studies on the improvement of skin health through the regulation of the intestinal condition in humans. In this study, we investigated the benefits of Lactobacillus plantarum HY7714 (HY7714) consumption on skin health through its modulatory effects on the intestine and ensuing immune responses. HY7714 consumption led to differences in bacterial abundances from phylum to genus level, including increases in Actinobacteria followed by Bifidobacterium and a decrease in Proteobacteria. Additionally, HY7714 significantly ameliorated inflammation by reducing matrix metallopeptidases (MMP-2 and MMP-9), zonulin, and calprotectin in plasma, all of which are related to skin and intestinal permeability. Furthermore, RNA-seq analysis revealed its efficacy at restoring the integrity of the gut barrier by regulating gene expression associated with the extracellular matrix and immunity. This was evident by the upregulation of IGFBP5, SERPINE1, EFEMP1, COL6A3, and SEMA3B and downregulation of MT2A, MT1E, MT1X, MT1G, and MT1F between TNF- α and TNF- α plus HY7714 treated Caco-2 cells. These results propose the potential mechanistic role of HY7714 on skin health by the regulation of the gut condition.

MiR-6872 host gene SEMA3B and its antisense lncRNA SEMA3B-AS1 function synergistically to suppress gastric cardia adenocarcinoma progression

BACKGROUND

Semaphorin 3B (SEMA3B) is frequently inactivated in several carcinomas. However, as the host gene of miR-6872, the roles of SEMA3B, antisense lncRNA SEMA3B-AS1, and miR-6872 in gastric cardia adenocarcinoma (GCA) tumorigenesis have not been clarified.

METHODS

The expression levels of SEMA3B, SEMA3B-AS1, and miR-6872 were respectively detected by qRT-PCR, western blot, or immunohistochemical staining assays. The methylation status was determined by BGS and BS-MSP methods. In vitro assays were preformed to explore the biological effects of SEMA3B, SEMA3B-AS1, and miR-6872-5p in gastric cancer cells. Chromatin immunoprecipitation assay was used to detect the binding of protein to DNA. The interaction of SEMA3B-AS1 with MLL4 was identified by RNA immunoprecipitation and RNA pull-down assays.

RESULTS

Frequent downregulation of SEMA3B, SEMA3B-AS1, and miR-6872 was detected in GCA tissues and gastric cancer cells. Aberrant hypermethylation of the promoter region was more tumor specific and was negatively correlated with the expression level of SEMA3B, SEMA3B-AS1, and miR-6872-5p. Transcription factor Sp1 activated SEMA3B or SEMA3B-AS1 transcription and CpG sites hypermethylation within promoter region eliminated Sp1 binding ability. Overexpression of SEMA3B and SEMA3B-AS1 inhibited gastric cancer cell proliferation, migration, and invasion in vitro. SEMA3B-AS1 induced the expression of SEMA3B by interacting with MLL4. ZNF143 might be the target gene of miR-6872-5p and miR-6872-5p functioning synergistically with SEMA3B to suppress cell invasion. Furthermore, SEMA3B, SEMA3B-AS1, and miR-6872-5p expression levels were associated with GCA patients' survival.

CONCLUSIONS

SEMA3B, SEMA3B-AS1, and miR-6872 may act as tumor suppressors and may serve as potential targets for antitumor therapy.

Epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) suppressed the growth of hepatocellular carcinoma cells by promoting Semaphorin 3B(SEMA3B)

AIM

Epidermal growth factor-containing fibulin-like extracellular matrix protein 1(EFEMP1) has been found to be involved in the occurrence and development of many cancers. The relationship between EFEMP1 and the development of hepatocellular carcinoma (HCC) and the molecular mechanism are not fully understood.

METHODS

Real-time polymerase chain reaction (PCR) and tissue microarray were used to detect the expression of EFEMP1 in HCC cell lines and tissue. Methylation-specific PCR assay was used to measure the methylation level of EFEMP1 in HCC cell lines and tissue. To study the function of EFEMP1 on cell function, Huh7 and HepG2 were infected with lentiviral particles expressing EFEMP1. MTT assay and colony formation assay were used to examine the effect of EFEMP1 on cell proliferation. Annexin-VAPC/7-AAD double were used to detect the effect of EFEMP1 on cell apoptosis. To further detect the effect of EFEMP1 on the development of HCC in vivo, we performed the tumor formation experiment in nude mice. Gene chip was used to detect the expression profile of Huh7 and HepG2 overexpressing EFEMP1. To further screen out the differences, GO analysis and pathway analysis were performed. To study the effects of SEMA3B, specific siRNA was used to inhibit the expression of SEMA3B. Chi-squared test and rank sum test were used to analyze the relationship between EFEMP1 expression and HCC clinical characteristic.

RESULTS

The study found that the expression of EFEMP1 was significantly decreased in HCC cell lines and HCC tissues. The expression level of EFEMP1 was related to the TNM (the extent of the tumor, the extent of spread to the lymph nodes, the presence of metastasis) stage and the prognosis of patients with HCC. The decrease of protein expression suggested that the patient prognosis was worse, and the protein level of EFEMP1 may be an independent factor in the prognosis of HCC patients. Promoter methylation may be one of the reasons for EFEMP1 inhibition. EFEMP1 could inhibit the proliferation of HCC cells and promoted the apoptosis of HCC cells to regulate the development of HCC. And EFEMP1 promoted the apoptosis of HCC cells mainly through the mitochondrial apoptosis pathway. EFEMP1 may inhibit the proliferation of HCC cells through the SEMA3B gene in the Axon guidance pathway.

CONCLUSION

In summary, our research revealed the regulation of EFEMP1 on cell proliferation and apoptosis in HCC. EFEMP1 may suppress the growth of HCC cells by promoting SEMA3B.

Promoter hypermethylation-mediated downregulation of tumor suppressor gene SEMA3B and lncRNA SEMA3B-AS1 correlates with progression and prognosis of esophageal squamous cell carcinoma

Frequent deletions of tumor-suppressor genes at chromosome 3p21.3 have been detected in esophageal squamous cell carcinoma (ESCC). As a candidate tumor suppressor gene, semaphorin 3B (SEMA3B) is located at 3p21.3 and is frequently inactivated in several tumors. However, the role and inactivation mechanisms of SEMA3B and its antisense long non-coding RNA (lncRNA) SEMA3B-AS1 in the carcinogenesis of ESCC have not been fully elucidated. The present study was conducted to investigate the role, epigenetic inactivation mechanisms, and prognostic value of SEMA3B and SEMA3B-AS1 in ESCC tumorigenesis and prognosis. Frequent downregulation of SEMA3B and SEMA3B-AS1 was detected in esophageal cancer cells and ESCC tissues, and the expression level of SEMA3B and SEMA3B-AS1 in ESCC tissues was correlated with TNM stage and lymph node metastasis. SEMA3B and SEMA3B-AS1 shared the same CpG island in the promoter region and the expression of both genes might be regulated by the promoter methylation status. Furthermore, transcription factor Sp1 activated SEMA3B or SEMA3B-AS1 transcription and the promoter hypermethylation of SEMA3B and SEMA3B-AS1 influenced Sp1 binding ability. Moreover, over-expression of SEMA3B and SEMA3B-AS1 suppressed the viability and invasion of esophageal cancer cells in vitro. SEMA3B-AS1 influenced the protein expression of SEMA3B. SEMA3B or SEMA3B-AS1 expression and promoter methylation status were correlated with ESCC patients' survival. Thus, these findings suggest that SEMA3B and SEMA3B-AS1 may act as tumor suppressors and may serve as potential targets for antitumor therapy.

Class-3 Semaphorins and Their Receptors: Potent Multifunctional Modulators of Tumor Progression

Semaphorins are the products of a large gene family containing 28 genes of which 21 are found in vertebrates. Class-3 semaphorins constitute a subfamily of seven vertebrate semaphorins which differ from the other vertebrate semaphorins in that they are the only secreted semaphorins and are distinguished from other semaphorins by the presence of a basic domain at their C termini. Class-3 semaphorins were initially characterized as axon guidance factors, but have subsequently been found to regulate immune responses, angiogenesis, lymphangiogenesis, and a variety of additional physiological and developmental functions. Most class-3 semaphorins transduce their signals by binding to receptors belonging to the neuropilin family which subsequently associate with receptors of the plexin family to form functional class-3 semaphorin receptors. Recent evidence suggests that class-3 semaphorins also fulfill important regulatory roles in multiple forms of cancer. Several class-3 semaphorins function as endogenous inhibitors of tumor angiogenesis. Others were found to inhibit tumor metastasis by inhibition of tumor lymphangiogenesis, by direct effects on the behavior of tumor cells, or by modulation of immune responses. Notably, some semaphorins such as sema3C and sema3E have also been found to potentiate tumor progression using various mechanisms. This review focuses on the roles of the different class-3 semaphorins in tumor progression.