Serum Glycome as a Diagnostic and Prognostic Factor in Gestational Diabetes Mellitus.

Gestational diabetes mellitus (GDM) is a risk factor for both mother and fetus/neonate during and after the pregnancy. Inconsistent protocols and cumbersome screening procedures warrant the search for new and easily accessible biomarkers. We investigated a potential of serum N-glycome to differentiate between healthy pregnant women (n = 49) and women with GDM (n = 53) using a lectin-based microarray and studied the correlation between the obtained data and parameters of glucose and lipid metabolism. Four out of 15 lectins used were able to detect the differences between the control and GDM groups in fucosylation, terminal galactose/N-acetylglucosamine (Gal/GlcNAc), presence of Galα1,4Galß1,4Glc (Gb3 antigen), and terminal α2,3-sialylation with AUC values above 60%. An increase in the Gb3 antigen and α2,3-sialylation correlated positively with GDM, whereas the amount of fucosylated glycans correlated negatively with the content of terminal Gal/GlcNAc. The content of GlcNAc oligomers correlated with the highest number of blood analytes, indices, and demographic characteristics, but failed to discriminate between the groups. The presence of terminal Gal residues correlated positively with the glucose levels and negatively with the LDL levels in the non-GDM group only. The results suggest fucosylation, terminal galactosylation, and the presence of Gb3 antigen as prediction markers of GDM.

The WAVE2/miR-29/Integrin-ß1 Oncogenic Signaling Axis Promotes Tumor Growth and Metastasis in Triple-negative Breast Cancer.

Breast cancer is the most frequently diagnosed malignancy in women and the major cause of death because of its invasion, metastasis, and resistance to therapies capabilities. The most aggressive subtype of breast cancer is triple-negative breast cancer (TNBC) due to invasive and metastatic properties along with early age of diagnosis and poor prognosis. TNBC tumors do not express estrogen, progesterone, and HER2 receptors, which limits their treatment with targeted therapies. Cancer invasiveness and metastasis are known to be promoted by increased cell motility and upregulation of the WAVE proteins. While the contribution of WAVE2 to cancer progression is well documented, the WAVE2-mediated regulation of TNBC oncogenic properties is still under investigated, as does the molecular mechanisms by which WAVE2 regulates such oncogenic pathways. In this study, we show that WAVE2 plays a significant role in TNBC development, progression, and metastasis, through the regulation of miR-29 expression, which in turn targets Integrin-ß1 (ITGB1) and its downstream oncogenic activities. Conversely, we found WAVE2 expression to be regulated by miR-29 in a negative regulatory feedback loop. Reexpression of exogenous WAVE2 in the WAVE2-deficient TNBC cells resulted in reactivation of ITGB1 expression and activity, further confirming the specificity of WAVE2 in regulating Integrin-ß1. Together, our data identify a novel WAVE2/miR-29/ITGB1 signaling axis, which is essential for the regulation of the invasion-metastasis cascade in TNBC. Our findings offer new therapeutic strategies for the treatment of TNBC by targeting WAVE2 and/or its downstream effectors. Significance: Identification of a novel WAVE2/miR-29/ITGB1 signaling axis may provide new insights on how WAVE2 regulates the invasion-metastasis cascade of TNBC tumors through the modulation of ITGB1 and miR-29.

The WAVE3/ß-catenin oncogenic signaling regulates chemoresistance in triple negative breast cancer.

BACKGROUND: Metastatic breast cancer is responsible for the death of the majority of breast cancer patients. In fact, metastatic BC is the 2nd leading cause of cancer-related deaths in women in the USA and worldwide. Triple negative breast cancer (TNBC), which lacks expression of hormone receptors (ER-α and PR) and ErbB2/HER2, is especially lethal due to its highly metastatic behavior, propensity to recur rapidly, and for its resistance to standard of care therapies, through mechanisms that remain incompletely understood. WAVE3 has been established as a promoter of TNBC development and metastatic progression. In this study, we investigated the molecular mechanisms whereby WAVE3 promotes therapy-resistance and cancer stemness in TNBC, through the regulation of ß-catenin stabilization. METHODS: The Cancer Genome Atlas dataset was used to assess the expression of WAVE3 and ß-catenin in breast cancer tumors. Kaplan-Meier Plotter analysis was used to correlate expression of WAVE3 and ß-catenin with breast cancer patients' survival probability. MTT assay was used to quantify cell survival. CRISPR/Cas9-mediated gene editing, 2D and 3D tumorsphere growth and invasion assays, Immunofluorescence, Western blotting, Semi-quantitative and real-time quantitative PCR analyses were applied to study the WAVE3/ß-catenin oncogenic signaling in TNBC. Tumor xenograft assays were used to study the role of WAVE3 in mediating chemotherapy resistance of TNBC tumors. RESULTS: Genetic inactivation of WAVE3 in combination of chemotherapy resulted in inhibition of 2D growth and 3D tumorsphere formation and invasion of TNBC cells in vitro, as well as tumor growth and metastasis in vivo. In addition, while re-expression of phospho-active WAVE3 in the WAVE3-deficient TNBC cells restored the oncogenic activity of WAVE3, re-expression of phospho-mutant WAVE3 did not. Further studies revealed that dual blocking of WAVE3 expression or phosphorylation in combination with chemotherapy treatment inhibited the activity and expression and stabilization of ß-catenin. Most importantly, the combination of WAVE3-deficiency or WAVE3-phospho-deficiency and chemotherapy suppressed the oncogenic behavior of chemoresistant TNBC cells, both in vitro and in vivo. CONCLUSION: We identified a novel WAVE3/ß-catenin oncogenic signaling axis that modulates chemoresistance of TNBC. This study suggests that a targeted therapeutic strategy against WAVE3 could be effective for the treatment of chemoresistant TNBC tumors.

Diagnostic Tests in the Prediction of Neonatal Outcome in Early Placental Fetal Growth Restriction.

Background and Objectives: Monitoring pregnancies with fetal growth restriction (FGR) presents a challenge, especially concerning the time of delivery in cases of early preterm pregnancies below 32 weeks. The aim of our study was to compare different diagnostic parameters in growth-restricted preterm neonates with and without morbidity/mortality and to determine sensitivity and specificity of diagnostic parameters for monitoring preterm pregnancies with early preterm fetal growth restriction below 32 weeks. Materials and Methods: Our clinical study evaluated 120 cases of early preterm deliveries, with gestational age ≤ 32 + 0 weeks, with prenatally diagnosed placental FGR. All the patients were divided into three groups of 40 cases each based on neonatal condition,: I-Neonates with morbidity/mortality (NMM); II-Neonates without morbidity with acidosis/asphyxia (NAA); III-Neonates without neonatal morbidity/acidosis/asphyxia (NWMAA). Results: Amniotic fluid index (AFI) was lower in NMM, while NWMAA had higher biophysical profile scores (BPS). UA PI was lower in NWMAA. NWMAA had higher MCA PI and CPR and fewer cases with CPR <5th percentile. NMM had higher DV PI, and more often had ductus venosus (DV) PI > 95th‱ or absent/reversed A wave, and pulsatile blood flow in umbilical vein (UV). The incidence of pathological fetal heart rate monitoring (FHRM) was higher in NMM and NAA, although the difference was not statistically significant. ROC calculated by defining a bad outcome as NMM and a good outcome as NAA and NWMAA showed the best sensitivity in DV PIi. ROC calculated by defined bad outcome in NMM and NAA and good outcome in NWMAA showed the best sensitivity in MCA PI. Conclusions: In early fetal growth restriction normal cerebral blood flow strongly predicts good outcomes, while pathological venous blood flow is associated with bad outcomes. In fetal growth restriction before 32 weeks, individualized expectant management remains the best option for the optimal timing of delivery.

Pediatric Casualties in Terrorist Attacks: A Semi-Quantitative Analysis of Global Events.

BACKGROUND: Terrorism remains a major threat and concern in many countries around the world. Pediatric populations represent approximately 30% of the world population, and in the event of a terrorist attack, can either be primary targets, to include the possibility of abduction, or unintended victims. They are unique in their vulnerabilities and, therefore, require special consideration. METHODS: This study is a semi-quantitative, epidemiological analysis of all terrorism-related pediatric fatalities and injuries sustained from 1970-2019. Data collection was performed using a retrospective database search through the Global Terrorism Database (GTD). Summaries of events including search terms associated with pediatric population were individually reviewed and those describing the deaths, injuries, or abductions were tallied. RESULTS: Of the over 200,000 terror events, 2,302 events met inclusion criteria. This represented 1.14% of total events which involved death, injury, or abduction. Of 2,032 events, a total of 2,275 pediatric fatal injuries (FI) were recorded, as well as 2,280 pediatric non-fatal injuries (NFI). The most common weapons used in all attacks involving the pediatric population were explosives (1,539 [66.8%]), firearms (543 [23.5%]), other (169 [7.3%]), and melee (83 [3.6%]). A total of 275 of the 2,032 events were related to abductions, with 71 cases involving the abduction of 10 individuals or more. CONCLUSION: Pediatric casualties in terrorist events represent a small proportion of overall victims. However, it should be understood that the pediatric population has unique vulnerabilities, and when directly impacted by terrorism, can have long-term physical and psychosocial sequelae, as well as a devastating emotional impact on the community.

Age, Body Mass Index, and Waist-to-Hip Ratio Related Changes in Insulin Secretion and Insulin Sensitivity in Women with Polycystic Ovary Syndrome: Minimal Model Analyses.

Insulin resistance is believed to be an integral component of the polycystic ovary syndrome (PCOS). Beta (ß) cell dysfunction is also found in PCOS. In the study, we determined the influence of age, body mass index (BMI), and waist-to-hip ratio (WHR) on insulin response to oral glucose load (OGTT) and on insulin sensitivity (Si) and ß-cell function in young women with PCOS. One hundred fourteen patients with PCOS and 41 controls with normal basal plasma glucose were studied. A 75-g OGTT was performed to determine glucose tolerance and insulin response. Insulin sensitivity and ß-cell function were studied using a modified frequently sampled IV glucose tolerance test (FISGTT) to determine the acute insulin response (AIRG), as well as Si by minimal model analysis. Si was decreased in PCOS women (2.49 0.18 vs. 3.41 ± 0.36, p < 0.05), but no difference in AIRG existed between the PCOS and control group (75.1 ± 4.6 vs. 63.4 ± 4.6, p < 0.05). BMI and WHR correlated negatively with Si (r = -0.43; r = -0.289, p < 0.001, respectively), but not with AIRG (r = 0.116; r = -0.02, p > 0.05, respectively). Increasing age correlated negatively with AIRG (r = -0.285, p < 0.001). There was a significant interaction between disease (PCOS), BMI, and WHR on Si as well as between age and PCOS on AIRG. Thus, patients below the age of 25 with PCOS showed enhanced AIRG (89.5 ± 7.1 vs. 65.1 ± 6.7, p < 0.05) and decreased Si (2.43 ± 0.25 vs. 4.52 ± 0.62, p < 0.05) compared to age-matched controls. In conclusion, these data suggest that not all patients with PCOS have basal and stimulated hyperinsulinemia, insulin resistance, and impaired glucose tolerance. Based on these data in young PCOS subjects, the development of insulin resistance and T2DM may be prevented with appropriate treatment strategies.

Gestational Diabetes is Associated with an Increased Expression of miR-27a in Peripheral Blood Mononuclear Cells.

BACKGROUND: Dysregulation of microRNA-based mechanisms is associated with various human pathologies, including gestational diabetes mellitus (GDM), suggesting they may be  potential diagnostic and/or prognostic biomarkers of GDM. METHODS: The expression of miR-340-5p, miR-27a-3p and miR-222-3p in peripheral blood mononuclear cells (PBMCs) obtained from patients with GDM (n = 42) and healthy controls (n = 34) were evaluated, together with their correlation to the clinical parameters of participants and their newborns. Expression of the selected microRNAs was quantified by quantitative real-time polymerase chain reaction (qPCR), after reverse transcription with microRNA-specific stem-loop primers. RESULTS: The expression of miR-27a-3p was significantly higher in patients with GDM than in controls (p = 0.036), whereas no significant difference between groups was found for the other two tested microRNAs. The expression level of miR-27a-3p in GDM patients was found to negatively correlate with the number of erythrocytes, concentration of haemoglobin, haematocrit, and low- and high-density lipoprotein (LDL/HDL) ratio, and positively with the concentration of glycated haemoglobin (HbA1c). In the case of miR-222-3p, a negative correlation between its expression and the concentration of cholesterol, LDL and LDL/HDL ratio was found only in healthy pregnant women. The expression level of miR-340-5p negatively correlated with erythrocyte count, haemoglobin concentration and haematocrit in GDM patients, as well as with the concentration of cholesterol, LDL and LDL/HDL ratio in healthy women. CONCLUSIONS: The results obtained illustrate the potential of PBMC-derived microRNA miR-27a-3p to serve as a diagnostic biomarker of GDM. On the other hand, MiR-27a and miR-340 may help in assessing the metabolic status relevant for pregnancy.

Targeted Deletion of Kindlin-2 in Mouse Mammary Glands Inhibits Tumor Growth, Invasion, and Metastasis Downstream of a TGF-ß/EGF Oncogenic Signaling Pathway.

Breast cancer (BC) is one of the leading causes of cancer-related deaths due in part to its invasive and metastatic properties. Kindlin-2 (FERMT2) is associated with the pathogenesis of several cancers. Although the role of Kindlin-2 in regulating the invasion-metastasis cascade in BC is widely documented, its function in BC initiation and progression remains to be fully elucidated. Accordingly, we generated a floxed mouse strain by targeting the Fermt2 (K2lox/lox) locus, followed by tissue-specific deletion of Kindlin-2 in the myoepithelial compartment of the mammary glands by crossing the K2lox/lox mice with K14-Cre mice. Loss of Kindlin-2 in mammary epithelial cells (MECs) showed no deleterious effects on mammary gland development, fertility, and lactation in mice bearing Kindlin-2-deletion. However, in a syngeneic mouse model of BC, mammary gland, specific knockout of Kindlin-2 inhibited the growth and metastasis of murine E0771 BC cells inoculated into the mammary fat pads. However, injecting the E0771 cells into the lateral tail vein of Kindlin-2-deleted mice had no effect on tumor colonization in the lungs, thereby establishing a critical role of MEC Kindlin-2 in supporting BC tumor growth and metastasis. Mechanistically, we found the MEC Kindlin-2-mediated inhibition of tumor growth and metastasis is accomplished through its regulation of the TGF-ß/ERK MAP kinase signaling axis. Thus, Kindlin-2 within the mammary gland microenvironment facilitates the progression and metastasis of BC.

Antioxidant status in hypertensive disorders of pregnancy.

OBJECTIVE: Pregnancy can be associated with maternal hypertension leading to possible complications in pregnancy outcome. Antioxidant status may be proned to changes during pregnancy with hypertension. The aim of our study was to estimate antioxidant status through high-risk pregnancies. METHODS: Seventy-nine pregnant women with high-risk for preeclampsia development were included and 46 of them developed some hypertensive disorder in pregnancy. Superoxide-dismutase (SOD) and paraoxonase 1 (PON1) activities and relative proportion of PON1 activiity on different HDL subclasses were determined in 1st, 2nd, and 3rd trimester and prior to delivery. RESULTS: SOD activity was significantly lower in 2nd and 3rd trimesters when compared to 1st trimester (P˂0.001) whereas PON1 activity was significantly higher in 3rd than in 1st trimester (P˂0.05) in group of hypertensive women. This group had significantly higher SOD and PON1 activities and relative proportion of PON1 on HDL3c subclasses in the 1st trimester, significantly increased PON1 in the 3rd trimester and prior to delivery and significantly higher PON1 activity on HDL3c subclasses (P˂0.05) than nonhypertensive group. In 1st trimester and prior to delivery, total PON1 activity and relative proportion of PON1 on HDL3c subclasses exhibited significant ability to mark out hypertension in pregnancy (P˂0.05). CONCLUSIONS: SOD activity decreased whereas total PON1 activity increased during pregnancy with hypertension. Pregnant women with hypertension had higher activities of PON1 and SOD and relative proportion of PON1 on HDL3c subclasses than nonhypertensive ones. PON1 activity and relative proportion of PON1 on HDL3c subclasses exhibited significant association with hypertension in pregnancy.

YB1 Is a Major Contributor to Health Disparities in Triple Negative Breast Cancer.

Triple negative breast cancer (TNBC) is the most aggressive amongst all breast cancer (BC) subtypes. While TNBC tumors represent less than 20% of all BC subtypes, they are responsible for the most BC-related deaths. More significantly, when considering TNBC incidence across all racial/ethnic groups, TNBC accounts for less than 20% of all BCs. However, in non-Hispanic black women, the incidence rate of TNBC is more than 40%, which may be a contributing factor to the higher BC-related death rate in this population. These disparities remain strong even after accounting for differences in socioeconomic status, healthcare access, and lifestyle factors. Increased evidence now points to biological mechanisms that are intrinsic to the tumor that contribute to disparate TNBC disease burdens. Here, we show that YB1, a multifunction gene, plays a major role in the TNBC disparities between African American (AA) and Caucasian American (CA) women. We show in three independent TNBC tumors cohorts, that YB1 is significantly highly expressed in AA TNBC tumors when compared to CAs, and that increased levels of YB1 correlate with poor survival of AA patients with TNBC. We used a combination of genetic manipulation of YB1 and chemotherapy treatment, both in vitro and in animal models of TNBC to show that YB1 oncogenic activity is more enhanced in TNBC cell lines of AA origin, by increasing their tumorigenic and aggressive behaviors, trough the activation of cancer stem cell phenotype and resistance to chemotherapeutic treatments.

Phosphatidylserine Exposing Extracellular Vesicles in Pre-eclamptic Patients.

Background: Pre-eclampsia (P-EC) is associated with systemic inflammation, endothelial dysfunction and hypercoagulability. The role of extracellular vesicles (EVs) in coagulation disturbances affecting the development and severity of P-EC remains elusive. We aimed to evaluate the concentration of EVs expressing phosphatidylserine (PS) and specific markers in relation to the thrombin and fibrin formation as well as fibrin clot properties, in pregnant women with P-EC in comparison to healthy pregnant women of similar gestational age. Methods: Blood samples of 30 pregnant women diagnosed with P-EC were collected on the morning following admission to hospital and after delivery (mean duration 5 days). The concentration of the PS-exposing EVs (PS+ EVs) from platelets (CD42a+, endothelial cells (CD62E+), and PS+ EVs expressing tissue factor (TF) and vascular cell adhesion molecule 1 (VCAM-1) were measured by flow cytometry. Further phenotyping of EVs also included expression of PlGF. Markers of maternal haemostasis were correlated with EVs concentration in plasma. Results: Preeclamptic pregnancy was associated with significantly higher plasma levels of PS+ CD42a+ EVs and PS+ VCAM-1+ EVs in comparison with normotensive pregnancy. P-EC patients after delivery had markedly elevated concentration of PS+ CD42a+ EVs, CD62E+ EVs, TF+ EVs, and VCAM-1+ EVs compared to those before delivery. Inverse correlation was observed between EVs concentrations (PS+, PS+ TF+, and PlGF+) and parameters of overall haemostatic potential (OHP) and fibrin formation, while PS+ VCAM-1+ EVs directly correlated with FVIII activity in plasma. Conclusion: Increased levels of PS+ EVs subpopulations in P-EC and their association with global haemostatic parameters, as well as with fibrin clot properties may suggest EVs involvement in intravascular fibrin deposition leading to subsequent microcirculation disorders.

Suicide Bombing Terrorism.

INTRODUCTION: While suicide bombings in the context of warfare have existed throughout history, there was an exponential rise in such attacks in the decade following the initiation of the War on Terror. The health care implications of such attacks are a growing concern across the emergency response sector, and this study is an epidemiological examination of all terrorism-related bombings sustained from 1970-2019, comparing the rates of fatal injuries (FI) and non-fatal injuries (NFI) between suicide bombing attacks (SBA) versus non-suicide bombing attacks (NSBA). METHOD: Data collection was performed using a retrospective database search through the Global Terrorism Database (GTD). The GTD database was downloaded and searched using the internal database search functions for all events that occurred from January 1, 1970 - December 31, 2019. Bombing/explosion as a primary "attack type" and explosives as a primary "weapon type" were selected for the purpose of this study, and events were further sub-classified as either "suicide attack" or "non-suicide attack." Results were exported into an Excel spreadsheet (Microsoft Corp.; Redmond, Washington USA) for analysis. FINDINGS: There were 82,217 bombing/explosion terrorist attacks using explosives documented during the study period with 135,807 fatalities and 352,500 NFI.A total of 5,416 events (6.59% of all events) were sub-classified as SBA causing 52,317 FI (38.52% of all FI) and 107,062 NFI (30.37% of all NFI).Mean SBA FI was 9.66 per event and mean SBA NFI was 19.77 per event compared to a mean NSBA FI of 1.09 per event and mean NSBA NFI of 3.20 per event. CONCLUSION: Suicide bombing attacks are a unique terrorist methodology that can inflict wide-spread psychological damage as well as significantly higher death and injury tolls when compared to more traditional NSBA. They have been increasing in popularity amongst terrorist organizations and groups, and Counter-Terrorism Medicine (CTM) specialists need to be aware of the unique injury patterns and potential risk mitigation strategies associated with SBA depending on the target type, location, and gender of the perpetrator.

The Role of WAVE2 Signaling in Cancer.

The Wiskott-Aldrich syndrome protein (WASP) and WASP family verprolin-homologous protein (WAVE)-WAVE1, WAVE2 and WAVE3 regulate rapid reorganization of cortical actin filaments and have been shown to form a key link between small GTPases and the actin cytoskeleton. Upon receiving upstream signals from Rho-family GTPases, the WASP and WAVE family proteins play a significant role in polymerization of actin cytoskeleton through activation of actin-related protein 2/3 complex (Arp2/3). The Arp2/3 complex, once activated, forms actin-based membrane protrusions essential for cell migration and cancer cell invasion. Thus, by activation of Arp2/3 complex, the WAVE and WASP family proteins, as part of the WAVE regulatory complex (WRC), have been shown to play a critical role in cancer cell invasion and metastasis, drawing significant research interest over recent years. Several studies have highlighted the potential for targeting the genes encoding either part of or a complete protein from the WASP/WAVE family as therapeutic strategies for preventing the invasion and metastasis of cancer cells. WAVE2 is well documented to be associated with the pathogenesis of several human cancers, including lung, liver, pancreatic, prostate, colorectal and breast cancer, as well as other hematologic malignancies. This review focuses mainly on the role of WAVE2 in the development, invasion and metastasis of different types of cancer. This review also summarizes the molecular mechanisms that regulate the activity of WAVE2, as well as those oncogenic pathways that are regulated by WAVE2 to promote the cancer phenotype. Finally, we discuss potential therapeutic strategies that target WAVE2 or the WAVE regulatory complex, aimed at preventing or inhibiting cancer invasion and metastasis.

A comprehensive review of the functions of YB-1 in cancer stemness, metastasis and drug resistance.

The Y Box binding protein 1 (YB-1) is a member of the highly conserved Cold Shock Domain protein family with multifunctional properties both in the cytoplasm and inside the nucleus. YB-1 is also involved in various cellular functions, including regulation of transcription, mRNA stability, and splicing. Recent studies have associated YB-1 with the regulation of the malignant phenotypes in several tumor types. In this review article, we provide an in-depth and expansive review of the literature pertaining to the multiple physiological functions of YB-1. We will also review the role of YB-1 in cancer development, progression, metastasis, and drug resistance in various malignancies, with more weight on literature published in the last decade. The methodology included querying databases PubMed, Embase, and Google Scholar for Y box binding protein 1, YB-1, YBX1, and Y-box-1.

Phosphorylation of the proline-rich domain of WAVE3 drives its oncogenic activity in breast cancer.

Post-translational modification of proteins, such as tyrosine phosphorylation, plays a major role in driving the oncogenic activity of oncogenes. WAVE3 (WASF3), an adaptor and actin cytoskeleton remodeling protein, contributes to cell migration, cancer cell invasion, and metastasis. WAVE3 plays a vital role in the progression and metastasis of triple negative breast cancer (TNBC), in part through the regulation of cancer stem cells (CSCs). Several studies have shown that WAVE3 tyrosine phosphorylation is required for its oncogenic activity. Moreover, our recent study showed that the proline rich domain (PRD) of WAVE3 is required for maintenance of the CSC niche in breast cancer by regulating the nuclear translocation of the CSC-specific nuclear transcription factor YB1. Here, we show that the PRD domain of WAVE3 and its phosphorylation are essential for driving the oncogenic activity of WAVE3. We show that phosphorylation of WAVE3 PRD is essential for migration and invasion of breast cancer cells in vitro, as well as tumor growth and metastasis in vivo. Mechanistically, we show that phosphorylation of the WAVE3 PRD is essential for interaction between WAVE3 and YB1. Loss of PRD phosphorylation inhibits such interaction and the YB1-mediated activation of expression of CSC markers, as well as the WAVE3 mediated activation of EMT. Together, our study identifies a novel role of WAVE3 and its PRD domain in the regulation of the invasion metastasis cascade in BC that is independent of the known function of WAVE3 as an actin cytoskeleton remodeling protein through the WAVE regulatory complex (WRC).

WAVE3 phosphorylation regulates the interplay between PI3K, TGF-ß, and EGF signaling pathways in breast cancer.

Both TGF-ß and the PI3K-AKT signaling pathways are known activators of various intracellular pathways that regulate critical cellular functions, including cancer cell survival and proliferation. The interplay between these two oncogenic pathways plays a major role in promoting the initiation, growth, and progression of tumors, including breast cancers. The molecular underpinning of the inter-relationship between these pathways is, however, not fully understood, as is the role of WAVE3 phosphorylation in the regulation of tumor growth and progression. WAVE3 has been established as a major driver of the invasion-metastasis cascade in breast cancer and other tumors of epithelial origin. WAVE3 phosphorylation downstream of PI3K was also shown to regulate cell migration. Here we show that, in addition to PI3K, WAVE3 tyrosine phosphorylation can also be achieved downstream of TGF-ß and EGF and that WAVE3 tyrosine phosphorylation is required for its oncogenic activity. Our in vitro analyses found loss of WAVE3 phosphorylation to significantly inhibit cell migration, as well as tumorsphere growth and invasion. In mouse models for breast cancer, loss of WAVE3 phosphorylation inhibited tumor growth of two aggressive breast cancer cell lines of triple-negative subtype. More importantly, we found that WAVE3 phosphorylation is also required for the activation of PI3K, TGF-ß, and EGF signaling and their respective downstream effectors. Therefore, our study identified a novel function for WAVE3 in the regulation of breast cancer development and progression through the modulation of a positive feedback loop between WAVE3 and PI3K-TGF-ß-EGF signaling pathways.

Role of Kindlin-2 in cancer progression and metastasis.

Cancer metastasis is a complex and multistep process whereby cancer cells escape the confines of the primary site to establish a new residency at distant sites. This multistep process is also known as the invasion-metastasis cascade. The biological and molecular mechanisms that control the invasion-metastasis cascade, which ultimately leads to the spread of cancer cells into distant sites, remain poorly understood. Kindlin-2 (K2) belongs to the 4.1-ezrin-ridixin-moesin (FERM) domain family of proteins, which interact with the cytoplasmic tails of ß-integrin subunits, leading to the activation of extensive biological functions. These biological functions include cell migration, differentiation, cancer initiation, development, and invasion. In this review, we will discuss the various molecular signaling pathways that are regulated by K2 during the invasion-metastasis cascade of cancer tumors. These signaling pathways include TGFß, Wnt/ß-Catenin, Hedgehog, p53 and senescence, and cancer stem cell (CSC) maintenance. We will also discuss the molecular signaling pathways that regulate K2 function both at the transcriptional and the posttranslational levels. Finally, we will consider molecular mechanisms to specifically target K2 as novel therapeutic options for cancer treatment.

Elucidating the molecular signaling pathways of WAVE3.

Cancer metastasis is a complex, multistep process that requires tumor cells to evade from the original site and form new tumors at a distant site or a different organ, often via bloodstream or the lymphatic system. Metastasis is responsible for more than 90% of cancer-related deaths. WAVE3 belongs to the Wiskott-Aldrich syndrome protein (WASP) family, which regulate actin cytoskeleton remodeling as well as several aspects of cell migration, invasion, and metastasis. In fact, WAVE3 has been established as a driver of tumor progression and metastasis in cancers from several origins, including triple negative breast cancers (TNBCs), which are classified as the most lethal subtype of breast cancer, due to their resistance to standard of care therapy and highly metastatic behavior. In this review, we will attempt to summarize the recent advances that have been made to understand how WAVE3 contributes to the molecular mechanisms that control cancer progression and metastasis. We will also review the signaling pathways that are involved in the regulation of WAVE3 expression and function to identify potential therapeutic options targeted against WAVE3 for the treatment of patients with metastatic tumors.