Association of pro-fibrinolytic receptor AnnexinA2 with tissue plasminogen activator/Inhibitor-1 in pre-eclampsia

Background

The clinical manifestations of pre-eclampsia are related to placental anti-angiogenic factor alteration. These variations are mainly due to the alteration of plasminolytic components. The study aims to compare the expression of plasminolytic components in the placenta of women with and without pre-eclampsia.

Material and Methods

The study included pregnant women with pre-eclampsia as PE group (n = 30) and without pre-eclampsia as a control group (n = 30). Placental bed biopsy tissues were collected. AnxA2, tPA, PAI-1 expression in the placental villous tissue was quantitatively evaluated using immunohistochemistry, western blot, and real time-PCR analysis.

Results

The results of the study showed a significant decrease in the expression of ANXA2 and increased expression of tPA and PAI-1 in PE group compared to control group (p<0.005). AnxA2 expression showed positive correlation with tPA (r=+0.895, p=0.002) and negative correlation with PAI-1(r=-0.905, p=0.020) in control group whereas in the PE group AnxA2 expression was negatively correlated with tPA ((r=-0.801, p=0.016) and PAI-1 (R=-0.831, P=0.010).

Conclusion

Decreased AnxA2 with increased expression of PAI-1 and tPA may be responsible for the altered fibrinolytic activity and play a significant role in pre-eclampsia pathogenesis.

Induction of Endometrial HOXA 10 Gene Expression by Vitamin D and its Possible Influence on Reproductive Outcome of PCOS Patients Undergoing Ovulation Induction Procedure

BACKGROUND AND OBJECTIVES

Polycystic ovarian syndrome (PCOS) is one of the most common endocrinopathies in women frequently presenting with anovulatory infertility. Low successful pregnancy and live birth rates even after successful ovulation induction (OI) and in vitro fertilization (IVF) in these patients indicate that endometrial dysfunction may be another important factor contributing to infertility. Vitamin D acting through nuclear receptors induces the expression of various genes required for cell growth and differentiation and plays a crucial role in reproduction. Homeobox 10 (HOXA10) may be one of the potential targets for vitamin D action. HOXA10 gene product promotes the differentiation of endometrial cells, making the endometrium receptive for implantation. The present study was undertaken to determine the effect of circulating vitamin D levels on HOXA10 gene expression in endometrial tissues and its possible influence on the reproductive outcome of PCOS patients undergoing OI procedure.

MATERIALS AND METHODS

A prospective cohort study was conducted on 110 infertile PCOS patients. The patients were divided into two groups: Group 1: Vitamin D ³20 ng/ml, Group 2: Vitamin D <20 ng/ml. Endometrial samples were obtained from 22 patients using pipelle biopsy, used to determine HOXA10 mRNA (messenger ribonucleic acid) expression by quantitative RT-PCR (reverse transcription-polymerase chain reaction) and protein expression by Western blotting. OI was performed using Clomiphene citrate or Letrozole from the 3^rd day of the cycle, and patients were followed up for a maximum of five cycles. Attainment of successful pregnancy was considered a positive outcome.

RESULTS

Both the groups were similar in mean age and other endocrine parameters. Serum vitamin D levels were significantly low (P < 0.001), and BMI (body mass index) was significantly high (P = 0.032) in group 2 compared to group 1. Endometrial HOXA10 mRNA (by quantitative rtPCR) and protein expression (by western blotting) were significantly low in group 2 compared to group 1. The clinical pregnancy rate was low in group 2 (28.6%) compared to group 1 (42.3%), but this difference was not significant (P = 0.22). On regression analysis adjusted for age and BMI, vitamin D was an independent predictor of successful pregnancy after OI (P = 0.09).

CONCLUSION

Circulating vitamin D levels influence the endometrial HOXA10 gene expression, and this may be reflected on the reproductive outcome of infertile PCOS patients undergoing OI.

Placental Expression and Relative Role of Anti-inflammatory Annexin A1 and Animal Lectin Galectin-3 in the Pathogenesis of Preeclampsia

Preeclampsia (PE) remains the major cause for maternal and foetal mortality and morbidity all over the world. Preeclampsia is associated with maternal, placental aggravated inflammatory response and generalized endothelial damage. AnnexinA1 (AnxA1) is glucocorticoid regulated protein regulates a wide range of cellular and molecular steps of the inflammatory response and is implicated in resolution of inflammation. Galectin-3 (Gal-3), β-galcotoside-binding lectin participates in many functions, both intra- and extracellularly. Recently it has been shown that galectin-3 modulates the inflammation. Role of AnxA1 and Galectin-3 is poorly studied in context with human reproductive disease like Preeclampsia. Therefore, the present study examined the expression of AnxA1 and Gal-3 which are involved in modulation of inflammation and their association in the placental bed of pregnancy with and without PE. The study group consisted of placental bed biopsy tissues obtained from pregnancies with PE (n = 30) and without (n = 30) PE. The expression of AnxA1 and Gal-3 in the placental bed tissues was evaluated quantitatively using Immunohisto-chemistry (IHC), western blot and mRNA expression analysis by quantitative RT-PCR. Our IHC, western blot and RT PCR analyses showed the increase in the expression of AnxA1 and Gal-3 in PE group compared with the normotensive control group (P < 0.001). The increased expression of AnxA1 and Gal-3 in placental bed may be associated with a systemic inflammatory response in PE, suggesting role of AnxA1 and Gal-3 in PE pathogenesis.

Ubiquitin mediated degradation of EGFR by 17 β-estradiol in triple negative MDA-MB-231 (TNBC) breast cancer cells line

BACKGROUND

Triple Negative Breast Cancer (TNBC) commonly displays Epidermal growth factor receptor (EGFR). Effective EGFR degradation results in suppression of tumor in various models. Studies have addressed the relevance of this strategy in the treatment of TNBC. In the present study, we examined the effect of 17 β-estradiol on EGFR expression in MDA-MB-231 (TNBC) cell line and assessed whether 17 β-estradiol degrades EGFR by ubiquitination pathway.

OBJECTIVES

To treat MDA-MB-231 cell lines with Cycloheximide with or without 17β-estrdiol to observe whether 17β-estradiol leads to EGFR degradation. To treat with MG-132 to assess whether degradation occurs through ubiquitination pathway.

METHODS

MDA-MB-231 cells were treated with 17β-estradiol (E2) and EGFR expression was studied by western blotting at different intervals by using Cycloheximide chase. To assess the ubiquitination pathway of degradation of EGFR in MDA-MB-231 cell line, MG-132 was used.

RESULTS

EGFR expression was reduced with β-estradiol treatment in MDA-MB-231 cell line with Cycloheximide chase. Upon Treatment with MG-132 and E2, EGFR expression did not reduce, suggesting that Estrogen degrades EGFR by ubiquitination pathway.

CONCLUSION

Estrogen degrades EGFR in MDA-MB-231 cells and this degradation occurs by ubiquitination.

Decreased expression of annexin A2 and loss of its association with vascular endothelial growth factor leads to the deficient trophoblastic invasion in preeclampsia

OBJECTIVES

Preeclampsia (PE) remains the major cause for maternal and foetal mortality and morbidity. Invasion of endovascular trophoblast and remodelling of spiral artery are crucial actions of normal placental development. Non-fulfilment of these processes plays a leading role in the development of preeclampsia. Vascular endothelial growth factor (VEGF) is produced by extravillous trophoblastic tissue and decidual cell population is a well-known angiogenic growth which plays a fundamental role in placental pathogenesis of PE. Annexin A2 (ANXA2) is a profibrinolytic protein receptor required for plasminolysis, which is an important step in the formation of new blood vessel along with VEGF. Role of ANXA2 is poorly studied in context with human reproductive disease like preeclampsia. The purpose of the present study is to examine the expression and association of VEGF and ANXA2 in the term placentas of pregnancies with and without PE.

METHODS

The study group comprised of placental tissues procured from gestations with PE (n=30) and without (n=20) PE. The expression of VEGF and ANXA2 in the placental villous tissue was evaluated quantitatively by means of IHC, western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

Our IHC, western blotting and RT-PCR analysis illustrated the significant decrease in the expression of VEGF and ANXA2 in PE group compared with the normotensive control group (p<0.005). We observed statistically significant positive correlation among the expression of ANXA2 and VEGF in placentas of normotensive control group (p<0.0001).

CONCLUSIONS

The diminished expression of VEGF and ANXA2 in placenta may be associated with the defective angiogenesis and which may possibly play a vital role in PE pathogenesis.

Comparative expression analysis of phospholipid binding protein annexina1 in nephrogenesis and kidney cancer

Background The expression in the glomerular mesangial cells, papillary, and collecting duct cells demonstrated annexin A1 (AnxA1)'s role in specific renal functions. With varying concentrations of calcium (Ca2+), it is considered to regulate cellular processes such as cell proliferation, apoptosis, and clearance of apoptotic cells by forming ceramides, a key lipid mediator of apoptosis. It also participates in tumorigenesis based on its location. On account of these features, we investigated the expression of this apoptosis-associated protein in fetal kidneys at different gestational periods, mature kidneys and in kidney cancer tissues in order to localize and possibly characterize its role during nephrogenesis and renal tumors. Methods AnxA1 expression was evaluated by an immunohistochemistry technique in "paraffin-embedded" renal tissue sections from autopsied fetuses at different gestational ages, in mature kidneys and renal cancer tissues. Results The current study data demonstrated that AnxA1 is expressed in the mesangial cells and podocytes of maturing glomeruli in the developing renal cortex of fetal kidneys at 14 to 19 weeks of gestation. The expression in the mesangial cells declined in later weeks of gestation and persisted into adulthood. AnxA1 expression increased with the progression of clear cell renal cell carcinoma (CCRCC) and also in other cancer types indicating a potential role of the protein in tumorigenesis. Conclusions We presume that AnxA1 in the podocytes and mesangial cells play important roles in various signaling pathways in the functioning of the glomerulus. These results and concepts provide a framework to further dissect its biological properties and thereby develop diagnostic, prognostic, and therapeutic strategies targeting the molecule in various renal pathologies.

Differential expression pattern of annexin A2 during nephrogenesis and kidney carcinoma

The creation of a cancer cell could be due to reactivation of repressed gene in the process of normal embryonic development. The differences in embryonic origins and functions of various components of nephron may contribute to the diversity of morphological patterns, molecular and immunohistochemical phenotypes of common renal neoplasms. Renal cell carcinomas (RCCs) are the most common amongst the genitourinary cancers. Annexin A2 (AnxA2) is a multifunctional calcium-regulated phospholipids-binding protein found in a subset of renal neoplasms. Since the tumor cells usually recapitulate embryonic cells, we studied the ontogeny of AnxA2 in developing renal tissues and compared it with those of normal adult RCCs, to better understand their role in renal development and tumorigenesis. AnxA2 immunoexpression was evaluated by immunohistochemistry from various autopsied fetuses, mature kidney and renal cancer tissue specimens. The study showed moderate membranous AnxA2 immunoexpression in the ureteric buds and collecting tubules of fetal kidneys (in all gestational ages) and in the collecting ducts of adult normal renal tissues. It is not often expressed in the proximal convoluted tubules of normal adult kidney; however, younger fetal kidneys show moderate AnxA2 immunoexpression in the proximal convoluted tubules (thought to be the origin of RCC) and the reappearance of strong membranous AnxA2 immunoexpression in the clear cell carcinoma is suggesting a deregulation of the gene during tumorigenesis. The understanding of the AnxA2 molecular immunoexpression pattern during development, its specific function and deregulated immunoexpression in different renal carcinoma types indicates the decisive role of AnxA2 in the cancer progression.

Annexin A2 and its downstream IL-6 and HB-EGF as secretory biomarkers in the differential diagnosis of Her-2 negative breast cancer

Background

AnnexinA2 (AnxA2) membrane deposition has a critical role in HB-EGF shedding as well as IL-6 secretion in breast cancer cells. This autocrine cycle has a major role in cancer cell proliferation, migration and metastasis. The objective of the study is to demonstrate annexinA2-mediated autocrine regulation via HB-EGF and IL-6 in Her-2 negative breast cancer progression.

Methods

Secretory annexinA2, HB-EGF and IL-6 were analysed in the peripheral blood sample of Her-2 negative ( n = 20) and positive breast cancer patients ( n = 16). Simultaneously, tissue expression was analysed by immunohistochemistry. The membrane deposition of these secretory ligands and their autocrine regulation was demonstrated using triple-negative breast cancer cell line model.

Results

Annexina2 and HB-EGF expression are inversely correlated with Her-2, whereas IL-6 expression is seen in both Her-2 negative and positive breast cancer cells. RNA interference studies and upregulation of annexinA2 proved that annexinA2 is the upstream of this autocrine pathway. Abundant soluble serum annexinA2 is secreted in Her-2 negative breast cancer (359.28 ± 63.73 ng/mL) compared with normal (286.10 ± 70.04 ng/mL, P < 0.01) and Her-2 positive cases (217.75 ± 60.59 ng/mL, P < 0.0001). In Her-2 negative cases, the HB-EGF concentrations (179.16 ± 118.81 pg/mL) were highly significant compared with normal (14.92 ± 17.33 pg/mL, P < 0.001). IL-6 concentrations were increased significantly in both the breast cancer phenotypes as compared with normal ( P < 0.001).

Conclusion

The specific expression pattern of annexinA2 and HB-EGF in triple-negative breast cancer tissues, increased secretion compared with normal cells, and their major role in the regulation of EGFR downstream signalling makes these molecules as a potential tissue and serum biomarker and an excellent therapeutic target in Her-2 negative breast cancer.

Cell surface interaction of annexin A2 and galectin-3 modulates epidermal growth factor receptor signaling in Her-2 negative breast cancer cells

Overexpression and activation of tyrosine kinase receptors like EGFR and Src regulate the progression and metastasis of Her-2 negative breast cancer. Recently we have reported the role of cell membrane interaction of phospholipid-binding protein annexin A2 (AnxA2) and EGFR in regulating cellular signaling in the activation of angiogenesis, matrix degradation, invasion, and cancer metastasis. Beta-galactoside-specific animal lectin galectin-3 is an apoptosis inhibitor, and cell surface-associated extracellular galectin-3 also has a role in cell migration, cancer progression, and metastasis. Similar expression pattern and membrane co-localization of these two proteins made us to hypothesize in the current study that galectin-3 and AnxA2 interaction is critical for Her-2 negative breast cancer progression. By various experimental analyses, we confirm that glycosylated AnxA2 at the membrane surface interacts with galectin-3. N-linked glycosylation inhibitor tunicamycin treatment convincingly blocked AnxA2 membrane translocation and its association with galectin-3. To analyze whether this interaction has any functional relevance, we tried to dissociate this interaction with purified plant lectin from chickpea (Cicer arietinum agglutinin). This highly specific 30 kDa plant lectin could dissociate AnxA2 from endogenous lectin galectin-3 interaction at the cell surface. This dissociation could down-regulate Bcl-2 family proteins, cell proliferation, and migration simultaneously triggering cell apoptosis. Targeting this interaction of membrane surface glycoprotein and its animal lectin in Her-2 negative breast cancer may be of therapeutic value.