Annexin A3 Knockdown Suppresses Lung Adenocarcinoma

Role of annexin A3 in breast cancer (Review)

Annexins are a large group of proteins occurring in numerous cell types. Annexins have roles in events such as coagulation inhibition, endocytosis, exocytosis, signal transduction, proliferation and programmed cell death. The association of annexins with numerous diseases has been reported. There are 12 annexin proteins in total and the association of annexin A3 (ANXA3) with numerous malignant tumor types, such as breast cancer, prostate cancer, lung cancer, stomach cancer and colon cancer, has been reported. Studies investigating the relationship between ANXA3 and breast cancer were analyzed in the present review and it was observed that ANXA3 is expressed at higher levels in breast cancer cells. Furthermore, high ANXA3 levels are a poor prognostic factor, increase the invasion ability of breast cancer cells and may be a novel therapeutic target.

Annexin A3 and cancer

Annexin A3 (ANXA3), an annexin family member, contains 36 kDa and 33 kDa isoforms. Similar to other annexin members, ANXA3 plays an important role in the development of human diseases. Recent studies have reported that abnormal ANXA3 expression is closely associated with the development, progression, metastasis, drug resistance and prognosis of several malignant tumours, such as breast cancer, lung cancer and hepatocellular carcinoma. ANXA3 exerts its role by regulating cell proliferation, migration and apoptosis via the phosphatidylinositol-3 kinase/Akt, nuclear factor-κB (NF-κB), c-JUN N-terminal kinase, extracellular signal-regulated kinase and hypoxia-inducible factor-1 signalling pathways. ANXA3 may act as a novel target for the early diagnosis and treatment of tumours. The present review summarises the recent progress in the role of ANXA3 and its regulatory pathways in tumours.

[CCL18 Promotes the Invasion of Lung Adenocarcinoma through ANXA2]

BACKGROUND

ANXA2 plays a very important role in cancer progression. chemokine ligand 18 (CCL18) is associated with the invasion, migration, metastasis and poor prognosis of lung adenocarcinoma (LUAD). In this study, we aimed to explore whether CCL18 promotes LUAD invasion through ANXA2, and its role and molecular mechanism in LUAD invasion.

METHODS

Western blot was used to detect ANXA2 expression in LUAD tissues and adjacent non-tumor tissues, the transfection efficiency of SiANXA2#2 in cells and the role of ANXA2 as an upstream regulator in the AKT/cofilin signaling pathway. In vitro cytological experiments such as chemotaxis experiment and transwell invasion test was used to explore the mechanism of ANXA2 on LUAD metastasis. F-actin polymerization experiment and Western blot were used to detect whether invasion ability alteration of SiANXA2#2 A549 cells are related to F-actin.

RESULTS

Western blot analysis showed that compared with adjacent non-tumor tissues, the protein expression level of ANXA2 in cancer tissues increased (P<0.05). In the chemotaxis experiment and invasion experiment, the chemotaxis and invasion ability induced by CCL18 decreased when ANXA2 knockdowned (P<0.05). Compared with the control group, F-actin polymerization was significantly lower in ANXA2 knockdown group, while phosphorylation of AKT at Ser473 and Thr308 and phosphorylation of Cofilin and LIMK were reduced in ANXA2 knockdown group (P<0.05).

CONCLUSIONS

ANXA2 knockdown can reduce the invasive effect of CCL18 on LUAD cells by reducing phosphorylation of AKT and downstream pathways.

Annexin Animal Models-From Fundamental Principles to Translational Research

Routine manipulation of the mouse genome has become a landmark in biomedical research. Traits that are only associated with advanced developmental stages can now be investigated within a living organism, and the in vivo analysis of corresponding phenotypes and functions advances the translation into the clinical setting. The annexins, a family of closely related calcium (Ca²⁺)- and lipid-binding proteins, are found at various intra- and extracellular locations, and interact with a broad range of membrane lipids and proteins. Their impacts on cellular functions has been extensively assessed in vitro, yet annexin-deficient mouse models generally develop normally and do not display obvious phenotypes. Only in recent years, studies examining genetically modified annexin mouse models which were exposed to stress conditions mimicking human disease often revealed striking phenotypes. This review is the first comprehensive overview of annexin-related research using animal models and their exciting future use for relevant issues in biology and experimental medicine.

33-kDa ANXA3 isoform contributes to hepatocarcinogenesis via modulating ERK, PI3K/Akt-HIF and intrinsic apoptosis pathways

Introduction

As a member of annexin family proteins, annexin A3 (ANXA3) has 36-kDa and 33-kDa isoforms. ANXA3 plays crucial roles in the tumorigenesis, aggressiveness and drug-resistance of cancers. However, previous studies mainly focused on the role of total ANXA3 in cancers without distinguishing the distinction between the two isoforms, the role of 33-kDa ANXA3 in cancer remains unclear.

Objectives

Current work aimed to investigate the function and regulation mechanism of 33-kDa ANXA3 in hepatocarcinoma.

Methods

The expressions of ANXA3, CRKL, Rac1, c-Myc and pAkt were analyzed in hepatocarcinoma specimens by Western blotting. The biological function of 33-kDa ANXA3 in the growth, metastasis, apoptosis, angiogenesis, chemoresistance of hepatocarcinoma cells with the underlying molecular mechanism were investigated using gain-of-function strategy in vitro or in vivo.

Results

33-kDa ANXA3 was remarkably upregulated in tumor tissues compared with corresponding normal liver tissues of hepatocarcinoma patients. Its stable knockdown decreased the in vivo tumor growing velocity and malignancy of hepatocarcinoma HepG2 cells transplanted in nude mice. The in vitro experimental results indicated 33-kDa ANXA3 knockdown suppressed the proliferation, colony forming, migration and invasion abilities of HepG2 cells through downregulating CRKL, Rap1b, Rac1, pMEK, pERK2 and c-Myc in ERK pathway; inhibited angiogenesisability of HepG2 cells through inactivating PI3K/Akt-HIF pathway; induced apoptosis and enhanced chemoresistance of HepG2 cells through increasing Bax/decreasing Bcl-2 expressions and inactivating caspase 9/caspase 3 in intrinsic apoptosis pathway. Accordingly, CRKL, Rac1, c-Myc and pAkt were also upregulated in hepatocarcinoma patients ’ tumor tissues compared with corresponding normal liver tissues.

Conclusions

The overexpression of 33-kDa ANXA3 is involved in the clinical progression of hepatocarcinoma and in the malignancy, angiogenesis and apoptosis of hepatocarcinoma cells. It is of potential use in hepatocarcinoma diagnosis and treatment.

Proteomic analysis of Nrk gene-disrupted placental tissue cells explains physiological significance of NRK

Objective

NRK is a unique X chromosome-linked protein kinase expressed predominantly in placenta. The gene knockout causes placental overgrowth and delayed labor of Nrk-null fetuses from dams in mouse. To clarify unknown mechanisms behind the Nrk-null phenotypes, protein expression profiles were analyzed in the Nrk-null placenta using a high-performance two-dimensional electrophoresis methodology.

Results

Among around 1800 spots detected, we characterized a dozen protein spots whose expression levels were significantly altered in the Nrk-null placenta compared to wild-type. Analyzing these data sets is expected to reflect the difference physiologically in the presence or absence of NRK, facilitating the development of therapeutic strategies.

The characteristics of lung cancer in Xuanwei County: A review of differentially expressed genes and noncoding RNAs on cell proliferation and migration

The occurrence of lung cancers is the highest in Xuanwei County, Yunnan province, China, especially among nonsmoking women. Domestic combustion of smoky coal induces serious indoor air pollution and is considered to be the main cause of human lung cancers. The occurrence of lung cancer in Xuanwei County has unique characteristics, such as the high morbidity in nonsmoking women or people with no family history. In the present review, we summarize advances in identification of differentially expressed genes, regulatory lncRNAs and miRNAs in cell proliferation and migration of lung cancers in Xuanwei County. Moreover, several regulatory differentially expressed genes (DEGs) or noncoding RNAs have diagnostic and prognostic significance for lung cancers in Xuanwei County and have the potential to serve as biomarkers.

Expression and significance of Annexin A3 in the osteosarcoma cell lines HOS and U2OS

Annexin A3 (ANXA3) is highly expressed in different types of cancers, but the impact of ANXA3 in bone tumors is still not clear. In the present study, the expression of ANXA3 in osteosarcoma cells was first confirmed by cellular immunofluorescence. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blot analysis were used to detect the expression of ANXA3 in osteoblasts in the osteosarcoma cell lines U2OS and HOS. Furthermore, small interfering (si)‑RNA were transfected into U2OS and HOS cells via a liposome‑mediated method. Then once ANXA3 had been successfully downregulated in U2OS and HOS cells, the cells were collected and total protein was extracted after 48 h of transfection. Western blot analysis was used to confirm successful ANXA3 transfection into osteosarcoma cells and the apoptotic rate of HOS and U2OS was detected by flow cytometry. The expression of ANXA3 in the osteosarcoma cell lines HOS and U2OS were first observed by confocal laser scanning microscopy, and was then detected by RT‑qPCR and western blotting. The mRNA and protein levels of ANXA3 in the osteosarcoma cell lines HOS and U2OS were significantly increased compared with osteoblasts, particularly in HOS cells. When siRNA was transfected into HOS and U2OS cells, the protein expression level of ANXA3 was measured via western blotting. The results indicated that the expression of ANXA3 was significantly decreased. In addition, to determine whether ANXA3 knockdown induced cell apoptosis, the present study analyzed the apoptotic rate by flow cytometry. The results revealed that ANXA3 knockdown markedly increased HOS and U2OS cell apoptosis. To the best of our knowledge, the present study is the first to confirm that ANXA3 is highly expressed in the osteosarcoma cell lines HOS and U2OS. In addition, downregulation of ANXA3 expression in HOS and U2OS cells could increase apoptotic ability.

Annexin A3 depletion overcomes resistance to oxaliplatin in colorectal cancer via the MAPK signaling pathway

Colorectal cancer (CRC) is a common disease with high mortality and morbidity. Annexin A3 (ANXA3) belongs to the structurally homologous family of Ca²⁺ and phospholipid-binding proteins. This study aimed to investigate the effects and potential mechanisms of ANXA3 on oxaliplatin (Ox) resistance in CRC. We generated two human CRC cell lines (HCT116/Ox and SW480/Ox) with acquired Ox resistance and determined their resistance properties. ANXA3 expression and cell apoptosis, migration and invasion also were evaluated. We found that cell viability of HCT116/Ox and SW480/Ox was higher than that in parental cells in the presence of Ox. ANXA3 was highly expressed in HCT116/Ox and SW480/Ox cells. ANXA3 downregulation diminished cell survival, migration and invasion, while increased the apoptosis of HCT116 and SW480 with or without Ox. Moreover, depletion of ANXA3 reduced cell viability and BrdU incorporation, increased cell apoptosis and c-caspase 3 expression in HCT116/Ox with or without Ox. A transwell assay determined that knockdown of ANXA3 impeded the migration and invasion of HCT116/Ox and SW480/Ox cells. Additionally, phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) decreased upon ANXA3 depletion in HCT116/Ox cells, and ANXA3 silencing suppressed Ox-induced activation of ERK and JNK signaling pathway. ANXA3 downregulation reduced Ox resistance in CRC, and treatment with the ERK inhibitor PD098059 or JNK inhibitor SP600125 contributed to this process. These results indicate that silencing ANXA3 could overcome Ox resistance in CRC via the mitogen-activated protein kinase signaling pathway.

Downregulation of annexin A3 inhibits tumor metastasis and decreases drug resistance in breast cancer

Annexin A3 (ANXA3) is dysregulated and plays an important role in various cancers. However, the role of ANXA3 in breast cancer is still unclear. Here, we observed that the expression level of ANXA3 was significantly upregulated in breast cancer tissues. ANXA3 knockdown inhibited cell invasion but promoted cell proliferation in both in vitro and in vivo assays. Furthermore, we found that ANXA3 knockdown inhibited the NFκB pathway via upregulating IκBα, resulting in mesenchymal–epithelial transition (MET) and a heterogeneity change of breast cancer stem cells (BCSCs). In addition, we demonstrated that ANXA3 knockdown increased the sensitivity of breast cancer cells to doxorubicin by increasing the drug uptake. The combination of ANXA3 knockdown and doxorubicin treatment simultaneously inhibited tumor growth and metastasis in vivo. This study described the role and mechanisms of ANXA3 in regulating BCSCs and breast cancer growth and metastasis, indicating that downregulating ANXA3 together with chemotherapy might be a novel therapeutic strategy for treating breast cancer.

Microarray-based SNP genotyping to identify genetic risk factors of triple-negative breast cancer (TNBC) in South Indian population

In the view of aggressive nature of Triple-Negative Breast cancer (TNBC) due to the lack of receptors (ER, PR, HER2) and high incidence of drug resistance associated with it, a case-control association study was conducted to identify the contributing genetic risk factors for Triple-negative breast cancer (TNBC). A total of 30 TNBC patients and 50 age and gender-matched controls of Indian origin were screened for 9,00,000 SNP markers using microarray-based SNP genotyping approach. The initial PLINK association analysis (p < 0.01, MAF 0.14-0.44, OR 10-24) identified 28 non-synonymous SNPs and one stop gain mutation in the exonic region as possible determinants of TNBC risk. All the 29 SNPs were annotated using ANNOVAR. The interactions between these markers were evaluated using Multifactor dimensionality reduction (MDR) analysis. The interactions were in the following order: exm408776 > exm1278309 > rs316389 > rs1651654 > rs635538 > exm1292477. Recursive partitioning analysis (RPA) was performed to construct decision tree useful in predicting TNBC risk. As shown in this analysis, rs1651654 and exm585172 SNPs are found to be determinants of TNBC risk. Artificial neural network model was used to generate the Receiver operating characteristic curves (ROC), which showed high sensitivity and specificity (AUC-0.94) of these markers. To conclude, among the 9,00,000 SNPs tested, CCDC42 exm1292477, ANXA3 exm408776, SASH1 exm585172 are found to be the most significant genetic predicting factors for TNBC. The interactions among exm408776, exm1278309, rs316389, rs1651654, rs635538, exm1292477 SNPs inflate the risk for TNBC further. Targeted analysis of these SNPs and genes alone also will have similar clinical utility in predicting TNBC.