Escherichia coli Nissle 1917 (EcN 1917) exhibits distinct tumor-targeting activity, and early studies demonstrated that outer membrane vesicles (OMVs) mediate bacteria-host interactions. To decipher the molecular mechanism underlying the interaction between EcN 1917 and host cells via OMV-mediated communication, we investigated the phenotypic changes in Caco-2 cells perturbed by EcN 1917-derived OMVs and constructed proteomic maps of the EcN 1917-derived OMV components and OMV-perturbed host cells. Our findings revealed that the size of the EcN 1917-derived OMV proteome increased 4-fold. Treatment with EcN 1917-derived OMVs altered the proteomic and phosphoproteomic profiles of host cells. Importantly, for the first time, we found that treatment with EcN 1917-derived OMVs inhibited cancer cell migration by suppressing the expression of ANXA9. In addition, phosphoproteomic data suggested that the ErbB pathway may be involved in OMV-mediated cell migration. Taken together, our study provides valuable data for further investigations of OMV-mediated bacteria-host interactions and offers great insights into the underlying mechanism of probiotic-assisted colorectal cancer therapy.

BACKGROUND: Sulfotransferase family 2B member 1 (SULT2B1) has been reported to play oncogenic role in many types of cancers. Nevertheless, the role that SULT2B1 played in ovarian cancer (OC) and the hidden molecular mechanism is obscure.
METHODS: Expression of SULT2B1 in OC was analyzed by GEPIA database. qRT-PCR and western blot (WB) was applied for the appraisement of SULT2B1 and Annexin A9 (ANXA9) in OC cell lines. The capabilities of cells to proliferate, migrate and invade were assessed with CCK-8 assay, wound healing assay, along with transwell assay. Cell apoptotic level was estimated utilizing flow cytometry. WB was employed for the evaluation of migration- and apoptosis-related proteins. Bioinformatic analysis and co-immunoprecipitation were used to predict and verify the combination of SULT2B1 and ANXA9.
RESULTS: The data showed that SULT2B1 and ANXA9 were upregulated in OC cells. SULT2B1 depletion suppressed the proliferative, migrative, and invasive capabilities of SKOV3 cells but facilitated the cell apoptosis. SULT2B1-regulated ANXA9 expression and were proved to bind to ANXA9. Additionally, ANXA9 deficiency exhibited the same impacts on cell migrative, invasive capability and apoptotic level as SULT2B1 silencing. Moreover, ANXA9 overexpression reversed the inhibitory impacts of SULT2B1 silencing on the proliferative, migrative, invasive, and apoptotic capabilities of SKOV3 cells.
CONCLUSIONS: In summary, SULT2B1 silencing repressed OC progression by targeting ANXA9.

Breast cancer (BC) ranks as the highest incidence among cancer types in women all over the world. MicroRNAs (miRNAs) are a class of short endogenous non-coding RNA in cells mostly functioning to silence the target mRNAs. In the current study, a miRNA screening analysis identified miR-186-5p to be downregulated in human breast cancer tumors. Functional studies in vitro demonstrated that overexpression of miR-186-5p inhibited cellular proliferation and induced cell apoptosis in multiple breast cancer cell lines including MDA-MB-231, MCF-7, and BT549 cells. Transplantation of the miR-186-5p-overexpressing MDA-MB-231 cells into nude mice significantly inhibited mammary tumor growth in vivo. Sequence blast analysis predicted annexin A9 (ANXA9) as a target gene of miR-186-5p, which was validated by luciferase reporter assay, QRT-PCR analysis, and western blot. Additional gene expression analysis of clinical tumor samples indicated a negative correlation between miR-186-5p and ANXA9 in human breast cancer. Knockdown of ANXA9 mimicked the phenotype of miR-186-5p overexpression. Reintroduction of ANXA9 back rescued the miR-186-5p-induced cell apoptosis. In addition, miR-186-5p decreased the expression of Bcl-2 and increased the expression of p53, suggesting a mechanism regulating miR-186-5p-induced cellular apoptosis. In summary, our study is the first to demonstrate miR-186-5p-ANXA9 signaling in suppressing human breast cancer. It provided a potential therapeutic target in breast cancer.

Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality worldwide. Expression of Annexin A9 (ANXA9), a member of the annexin A family, is upregulated in CRC. However, the molecular role of ANXA9 in CRC remains unknown. In the present study, we aimed to investigate the function of ANXA9 and to elucidate the mechanisms underlying its regulation in CRC. In this study, mRNA expression data and clinical information were downloaded from The Cancer Genome Atlas (TCGA) and GEPIA database, respectively. Kaplan-Meier analysis was used to analyze the survival rates. LinkedOmics and Metascape databases were used to explore the potential mechanisms of regulation of ANXA9 and to identify genes co-expressed with ANXA9. Finally, in vitro experiments were used to evaluate the function of ANXA9 and explore potential mechanisms. We found that ANXA9 expression was significantly elevated in CRC tissue and cells. High ANXA9 expression was associated with shorter overall survival, poorer disease specific survival, as well as with patient age, clinical stage, M stage, and OS events in CRC. Knockdown of ANXA9 inhibited cell proliferation, invasion, migratory potential, and cell cycle arrest. Mechanistically, functional analysis revealed that genes co-expressed with ANXA9 were mainly enriched in the Wnt signaling pathway. ANXA9 deletion suppressed cell proliferation via the Wnt signaling pathway, while Wnt activation reversed the effects of ANXA9. In conclusion, ANXA9 may promote CRC progression by regulating the Wnt signaling pathway and may be a potential diagnostic biomarker in the clinical management of CRC.

Breast cancer (BCA) is one of the most prevalent cancers among women. Emerging evidence has revealed that Annexin A-9 (ANXA9) plays a crucial function in the development of some cancers. Notably, ANXA9 has been reported to be a new prognostic biomarker for gastric and colorectal cancers. However, its expression and biological function in BCA have not yet been investigated. Using online bioinformatics tools such as TIMER, GEPIA, HPA, and UALCAN, we predicted ANXA9 expression and its correlation with the clinicopathological characteristics of BCA patients. RT-qPCR and western blot were utilized to measure ANXA9 mRNA and ANXA9 protein expression in BCA patient tissues and cells. BCA-derived exosomes were identified by transmission electron microscopy. Functional assays were employed to evaluate the biological role of ANXA9 in BCA cell proliferation, migration, invasion, and apoptosis. A tumor xenograft in vivo model was utilized to assess the role of ANXA9 in tumor growth in mice. Bioinformatics and functional screening analysis revealed that ANXA9 was highly expressed in BCA patient tissues, with median ANXA9 expression 1.5- to 2-fold higher than in normal tissues (p < 0.05). RT-qPCR confirmed that ANXA9 expression in BCA tissues was around 1.5-fold higher than the adjacent normal tissues (p < 0.001). ANXA9 expression in different subtypes of BCA also showed a difference, and ANXA9 was found to be mostly significantly upregulated in luminal BCA relative to normal tissues or other histological subtypes (p < 0.001). Moreover, ANXA9 expression was elevated in different races, ages, clinical stages, node metastasis status, and menopause status groups relative to the normal group (p < 0.001). Furthermore, ANXA9 was found to be secreted by BCA tissue-derived exosomes and its expression was upregulated 1- to 7-fold in BCA cells treated with exosomes (p < 0.001), while its expression in MCF10A cells was not significantly altered by treatment with exosomes (p > 0.05). ANXA9 silencing induced a significant decrease of around 30% in the colony number of BCA cells (p < 0.01). The number of migrated and invaded BCA cells also decreased by around 65 and 68%, respectively, after silencing ANXA9 (p < 0.01). Tumor size was significantly reduced (nearly half) in the LV-sh-ANXA9 group relative to the LV-NC group in the xenograft model (p < 0.01), suggesting that ANXA9 silencing repressed tumor progression in BCA progression in vitro and in vivo. In conclusion, exosome-derived ANXA9 functions as an oncogene that facilitates the proliferation, migration, and invasiveness of BCA cells and enhances tumor growth in BCA development, which may provide a new prognostic and therapeutic biomarker for BCA patients.

BACKGROUND: Gastric cancer (GC) is the most prevalent malignancy among the digestive system tumors. Increasing evidence has revealed that lower mRNA expression of ANXA9 is associated with a poor prognosis in colorectal cancer. However, the role of ANXA9 in GC remains largely unknown.
METHODS: The Gene Expression Profiling Interactive Analysis (GEPIA) and Human Protein Atlas databases were used to investigate the expression of ANXA9 in GC, which was then validated in the four Gene Expression Omnibus (GEO) datasets. The diagnostic value of ANXA9 for GC patients was demonstrated using a receiver operating characteristic (ROC) curve. The correlation between ANXA9 expression and clinicopathological parameters was analyzed in The Cancer Genome Atlas (TCGA) and UALCAN databases. The Kaplan-Meier (K-M) survival curve was used to elucidate the relationship between ANXA9 expression and the survival time of GC patients. We then performed a gene set enrichment analysis (GSEA) to explore the biological functions of ANXA9. The relationship of ANXA9 expression and cancer immune infiltrates was analyzed using the Tumor Immune Estimation Resource (TIMER). In addition, the potential mechanism of ANXA9 in GC was investigated by analyzing its related genes.
RESULTS: ANXA9 was significantly up-regulated in GC tissues and showed obvious diagnostic value. The expression of ANXA9 was related to the age, gender, grade, TP53 mutation, and histological subtype of GC patients. We also found that ANXA9 expression was associated with immune-related biological function. ANXA9 expression was also correlated with the infiltration level of CD8+ T cells, neutrophils, and dendritic cells in GC. Additionally, copy number variation (VNV) of ANXA9 occurred in GC patients. Function enrichment analyses revealed that ANXA9 plays a role in the GC progression by interacting with its related genes.
CONCLUSIONS: Our results provide strong evidence of ANXA9 expression as a prognostic indicator related to immune responses in GC.

Annexin A9 (ANXA9) is involved with the interaction with membrane phospholipids in a Ca2+-dependent manner. A previous study has shown that ANXA9 expression is associated with bone metastasis in breast cancer, whereas its significance in colorectal cancer (CRC) is unknown. The present study was comprised of 100 patients who underwent surgery for CRC. The correlation between gene expression and the clinical parameters of the patients was assessed. Patients with high ANXA9 expression were statistically susceptible to a relatively worse prognosis, and those with low ANXA9 expression showed improved overall survival compared with those with high expression. In conclusion, the present data suggests that ANXA9 expression is a prognostic factor in CRC patients.