Downregulation of DPF3 promotes the proliferation and motility of breast cancer cells through activating JAK2/STAT3 signaling

DPF3 polymorphisms increased the risk of pulmonary tuberculosis in the Northwest Chinese Han population

PURPOSE

This study aimed to investigate the association between single nucleotide polymorphisms (SNPs) in DPF3 and susceptibility to pulmonary tuberculosis (PTB) in the Northwest Chinese Han population.

METHODS

Genotyping of four DPF3 SNPs (rs10140566, rs75575287, rs202075571, and rs61986330) was performed using Agena MassARRAY from 488 PTB patients and 488 healthy controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression. Multifactor dimensionality reduction (MDR) analysis was employed to investigate the effect of SNP-SNP interactions on PTB risk. The GSE54992 dataset was analyzed using R software to ascertain DPF3 expression levels.

RESULTS

Overall analysis revealed that rs202075571 (allele: OR = 1.31, p = 0.015; CC vs. TT: OR = 1.97, p = 0.049; dominant: OR = 1.33, p = 0.032) and rs61986330 (allele: OR = 1.38, p = 0.010; CA vs. CC: OR = 1.35, p = 0.044; dominant: OR = 1.40, p = 0.019) were associated with an increased PTB risk. Stratified analysis showed that rs10140566 was a PTB risk factor in females, those aged ≤40 and non-smokers, and rs202075571 was associated with PTB risk in individuals aged >40 and smokers, and rs61986330 was associated with PTB risk in males, those aged >40 and smokers. The four SNPs model demonstrated significant predictive potential for PTB risk. Furthermore, DPF3 exhibited higher expression in PTB compared to healthy controls.

CONCLUSION

DPF3 polymorphisms (rs10140566, rs202075571, and rs61986330) are associated with an increased risk of PTB, providing valuable new insights into the mechanism of PTB.

Circ_0102543 suppresses hepatocellular carcinoma progression through the miR-942-5p/SGTB axis

Introduction

Hepatocellular carcinoma (HCC) is one of the most serious cancers. Circular RNA (circRNA) has been reported to regulate the progression of HCC. Herein, the role of circ_0102543 in HCC tumorigenesis was investigated.

Materials

The expression levels of circ_0102543, microRNA-942-5p (miR-942-5p), and small glutamine rich tetratricopeptide repeat co-chaperone beta (SGTB) were detected by quantitative real-time PCR (qRT-PCR). 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide (MTT) assay, thymidine analog 5-ethynyl-2'-deoxyuridine (EDU) assay, transwell assay, and flow cytometry were conducted to explore the function of circ_0102543 in HCC cells and the regulatory mechanism among circ_0102543, miR-942-5p and SGTB in HCC cells. Western blot examined the related protein levels.

Results

The expression of circ_0102543 and SGTB was decreased in HCC tissues, while the expression of miR-942-5p was increased. Circ_0102543 acted as a sponge for miR-942-5p, and SGTB was the target of miR-942-5p. Circ_0102543 up-regulation hindered tumor growth in vivo. In vitro experiments showed that overexpression of circ_0102543 significantly repressed the malignant behaviors of HCC cells, while co-transfection of miR-942-5p partially attenuated these effects mediated by circ_0102543. In addition, SGTB knockdown increased the proliferation, migration, and invasion of HCC cells inhibited by miR-942-5p inhibitor. Mechanically, circ_0102543 regulated SGTB expression in HCC cells by sponging miR-942-5p.

Conclusion

Overexpression of circ_0102543 suppressed proliferation, migration, and invasion of HCC cells by regulating the miR-942-5p/SGTB axis, suggesting that circ_0102543/miR-942-5p/SGTB axis may be a potential therapeutic target for HCC.

Alterations in the Epigenetic Machinery Associated with Prostate Cancer Health Disparities

Prostate cancer is driven by acquired genetic alterations, including those impacting the epigenetic machinery. With African ancestry as a significant risk factor for aggressive disease, we hypothesize that dysregulation among the roughly 656 epigenetic genes may contribute to prostate cancer health disparities. Investigating prostate tumor genomic data from 109 men of southern African and 56 men of European Australian ancestry, we found that African-derived tumors present with a longer tail of epigenetic driver gene candidates (72 versus 10). Biased towards African-specific drivers (63 versus 9 shared), many are novel to prostate cancer (18/63), including several putative therapeutic targets (CHD7, DPF3, POLR1B, SETD1B, UBTF, and VPS72). Through clustering of all variant types and copy number alterations, we describe two epigenetic PCa taxonomies capable of differentiating patients by ancestry and predicted clinical outcomes. We identified the top genes in African- and European-derived tumors representing a multifunctional "generic machinery", the alteration of which may be instrumental in epigenetic dysregulation and prostate tumorigenesis. In conclusion, numerous somatic alterations in the epigenetic machinery drive prostate carcinogenesis, but African-derived tumors appear to achieve this state with greater diversity among such alterations. The greater novelty observed in African-derived tumors illustrates the significant clinical benefit to be derived from a much needed African-tailored approach to prostate cancer healthcare aimed at reducing prostate cancer health disparities.

AKTIP loss is enriched in ERα-positive breast cancer for tumorigenesis and confers endocrine resistance

Recurrent deletion of 16q12.2 is observed in luminal breast cancer, yet the causal genomic alterations in this region are largely unknown. In this study, we identify that loss of AKTIP, which is located on 16q12.2, drives tumorigenesis of estrogen receptor alpha (ERα)-positive, but not ERα-negative, breast cancer cells and is associated with poor prognosis of patients with ERα-positive breast cancer. Intriguingly, AKTIP-depleted tumors have increased ERα protein level and activity. Cullin-associated and neddylation-dissociated protein 1 (CAND1), which regulates the cullin-RING E3 ubiquitin ligases, protects ERα from cullin 2-dependent proteasomal degradation. Apart from ERα signaling, AKTIP loss triggers JAK2-STAT3 activation, which provides an alternative survival signal when ERα is inhibited. AKTIP-depleted MCF7 cells and ERα-positive patient-derived organoids are more resistant to ERα antagonists. Importantly, the resistance can be overcome by co-inhibition of JAK2/STAT3. Together, our results highlight the subtype-specific functional consequences of AKTIP loss and provide a mechanistic explanation for the enriched AKTIP copy-number loss in ERα-positive breast cancer.

Unveiling the Metal-Dependent Aggregation Properties of the C-terminal Region of Amyloidogenic Intrinsically Disordered Protein Isoforms DPF3b and DPF3a

Double-PHD fingers 3 (DPF3) is a BAF-associated human epigenetic regulator, which is increasingly recognised as a major contributor to various pathological contexts, such as cardiac defects, cancer, and neurodegenerative diseases. Recently, we unveiled that its two isoforms (DPF3b and DPF3a) are amyloidogenic intrinsically disordered proteins. DPF3 isoforms differ from their C-terminal region (C-TERb and C-TERa), containing zinc fingers and disordered domains. Herein, we investigated the disorder aggregation properties of C-TER isoforms. In agreement with the predictions, spectroscopy highlighted a lack of a highly ordered structure, especially for C-TERa. Over a few days, both C-TERs were shown to spontaneously assemble into similar antiparallel and parallel β-sheet-rich fibrils. Altered metal homeostasis being a neurodegeneration hallmark, we also assessed the influence of divalent metal cations, namely Cu²⁺, Mg²⁺, Ni²⁺, and Zn²⁺, on the C-TER aggregation pathway. Circular dichroism revealed that metal binding does not impair the formation of β-sheets, though metal-specific tertiary structure modifications were observed. Through intrinsic and extrinsic fluorescence, we found that metal cations differently affect C-TERb and C-TERa. Cu²⁺ and Ni²⁺ have a strong inhibitory effect on the aggregation of both isoforms, whereas Mg²⁺ impedes C-TERb fibrillation and, on the contrary, enhances that of C-TERa. Upon Zn²⁺ binding, C-TERb aggregation is also hindered, and the amyloid autofluorescence of C-TERa is remarkably red-shifted. Using electron microscopy, we confirmed that the metal-induced spectral changes are related to the morphological diversity of the aggregates. While metal-treated C-TERb formed breakable and fragmented filaments, C-TERa fibrils retained their flexibility and packing properties in the presence of Mg²⁺ and Zn²⁺ cations.

Inhibition of NF-kB/IL-6/JAK2/STAT3 Pathway and Epithelial-Mesenchymal Transition in Breast Cancer Cells by Azilsartan

Metastatic breast cancer is an incurable form of breast cancer that exhibits high levels of epithelial-mesenchymal transition (EMT) markers. Angiotensin II has been linked to various signaling pathways involved in tumor cell growth and metastasis. The aim of this study is to investigate, for the first time, the anti-proliferative activity of azilsartan, an angiotensin II receptor blocker, against breast cancer cell lines MCF-7 and MDA-MB-231 at the molecular level. Cell viability, cell cycle, apoptosis, colony formation, and cell migration assays were performed. RT-PCR and western blotting analysis were used to explain the molecular mechanism. Azilsartan significantly decreased the cancer cells survival, induced apoptosis and cell cycle arrest, and inhibited colony formation and cell migration abilities. Furthermore, azilsartan reduced the mRNA levels of NF-kB, TWIST, SNAIL, SLUG and bcl2, and increased the mRNA level of bax. Additionally, azilsartan inhibited the expression of IL-6, JAK2, STAT3, MMP9 and bcl2 proteins, and increased the expression of bax, c-PARP and cleaved caspase 3 protein. Interestingly, it reduced the in vivo metastatic capacity of MDA-MBA-231 breast cancer cells. In conclusion, the present study revealed, for the first time, the anti-proliferative, apoptotic, anti-migration and EMT inhibition activities of azilsartan against breast cancer cells through modulating NF-kB/IL-6/JAK2/STAT3/MMP9, TWIST/SNAIL/SLUG and apoptosis signaling pathways.

STAT family of transcription factors in breast cancer: Pathogenesis and therapeutic opportunities and challenges

Breast cancer is the most commonly diagnosed cancer and second-leading cause of cancer deaths in women. Breast cancer stem cells (BCSCs) promote metastasis and therapeutic resistance contributing to tumor relapse. Through activating genes important for BCSCs, transcription factors contribute to breast cancer metastasis and therapeutic resistance, including the signal transducer and activator of transcription (STAT) family of transcription factors. The STAT family consists of six major isoforms, STAT1, STAT2, STAT3, STAT4, STAT5, and STAT6. Canonical STAT signaling is activated by the binding of an extracellular ligand to a cell-surface receptor followed by STAT phosphorylation, leading to STAT nuclear translocation and transactivation of target genes. It is important to note that STAT transcription factors exhibit diverse effects in breast cancer; some are either pro- or anti-tumorigenic while others maintain dual, context-dependent roles. Among the STAT transcription factors, STAT3 is the most widely studied STAT protein in breast cancer for its critical roles in promoting BCSCs, breast cancer cell proliferation, invasion, angiogenesis, metastasis, and immune evasion. Consequently, there have been substantial efforts in developing cancer therapeutics to target breast cancer with dysregulated STAT3 signaling. In this comprehensive review, we will summarize the diverse roles that each STAT family member plays in breast cancer pathobiology, as well as, the opportunities and challenges in pharmacologically targeting STAT proteins and their upstream activators in the context of breast cancer treatment.

Role of STAT3 in the initiation, progression, proliferation and metastasis of breast cancer and strategies to deliver JAK and STAT3 inhibitors

INTRODUCTION

Breast cancer (BC) accounts for the majority of cancers among the female population. Anomalous activation of various signaling pathways has become an issue of concern. The JAK-STAT signaling pathway is activated in numerous cancers, including BC. STAT3 is widely involved in BCs, as 40 % of BCs display phosphorylated STAT3. JAK-STAT signaling is crucial for proliferation, survival, metastasis and other cellular events associated with the tumor microenvironment. Hence, targeting this pathway has become an area of interest among researchers.

KEY FINDINGS

This review article focuses on the role of STAT3 in the initiation, proliferation, progression and metastasis of BC. The roles of various phytochemicals, synthetic molecules and biologicals against JAK-STAT and STAT3 in various cancers have been discussed, with special emphasis on BC.

SIGNIFICANCE

JAK and STAT3 are involved in various phases from initiation to metastasis, and targeting this pathway is a promising approach to inhibit the various stages of BC development and to prevent metastasis. A number of phytochemicals and synthetic and biological molecules have demonstrated potential inhibitory effects on JAK and STAT3, thereby paving the way for the development of better therapeutics against BC.

Structural characterisation of amyloidogenic intrinsically disordered zinc finger protein isoforms DPF3b and DPF3a

Double PHD fingers 3 (DPF3) is a zinc finger protein, found in the BAF chromatin remodelling complex, and is involved in the regulation of gene expression. Two DPF3 isoforms have been identified, respectively named DPF3b and DPF3a. Very limited structural information is available for these isoforms, and their specific functionality still remains poorly studied. In a previous work, we have demonstrated the first evidence of DPF3a being a disordered protein sensitive to amyloid fibrillation. Intrinsically disordered proteins (IDPs) lack a defined tertiary structure, existing as a dynamic conformational ensemble, allowing them to act as hubs in protein-protein interaction networks. In the present study, we have more thoroughly characterised DPF3a in vitro behaviour, as well as unravelled and compared the structural properties of the DPF3b isoform, using an array of predictors and biophysical techniques. Predictions, spectroscopy, and dynamic light scattering have revealed a high content in disorder: prevalence of random coil, aromatic residues partially to fully exposed to the solvent, and large hydrodynamic diameters. DPF3a appears to be more disordered than DPF3b, and exhibits more expanded conformations. Furthermore, we have shown that they both time-dependently aggregate into amyloid fibrils, as revealed by typical circular dichroism, deep-blue autofluorescence, and amyloid-dye binding assay fingerprints. Although spectroscopic and microscopic analyses have unveiled that they share a similar aggregation pathway, DPF3a fibrillates at a faster rate, likely through reordering of its C-terminal domain.

TRG16, targeted by miR-765, inhibits breast cancer stem cell-like properties via regulating the NF-κB pathway

Previous studies reported that cancer stem cells (CSCs) might be responsible for drug resistance and cancer progression. Transformation-Related Gene 16 Protein (TRG16), a pseudokinase, was reported to be a suppressor in some types of cancer and its overexpression impaired hepatocellular carcinoma cell stemness. However, the function of TRG16 in BC remains unclear. We found that TRG16 expression was significantly downregulated in BC tissues compared with adjacent tissues (n = 40; P < 0.001) and BC patients with lower expression of TRG16 had a worse prognosis. Forced expression of TRG16 inhibited BC stem cell-like properties as evidenced by decreased CD44-positive cells (CSC marker), reduced mammosphere quantity, and downregulated Nanog, aldehyde dehydrogenase, octamer-binding transcription factor 4, and SRY-box transcription factor 2 expression (CSC markers). Moreover, TRG16 overexpression inhibited self-renewal and invasion capabilities of BC cells in vitro as well as tumor growth in vivo but increased cisplatin sensitivity. However, TRG16 silencing had the opposite effects. Further mechanistic studies revealed that TRG16 was targeted and negatively regulated by miR-765, a facilitator of BC progression. TRG16 could suppress the activation of the NF-κB pathway in BC cells, which is a positive pathway in BC progression and contributes to the maintenance of cancer cell stemness. In conclusion, the results above demonstrate that TRG16, negatively regulated by miR-765, may inhibit the BC progression by regulating BC stem cell-like properties and this inhibition may be mediated by the NF-κB pathway. Our findings indicate that TRG16 may be a potential therapeutic targetable node for BC. TRG16, negatively regulated by miR-765, may inhibit the BC progression through regulating BC stem cell-like properties and this inhibition may be mediated by the NF-κB pathway.

Hypoxic Breast Cancer Cell-Derived Exosomal SNHG1 Promotes Breast Cancer Growth and Angiogenesis via Regulating miR-216b-5p/JAK2 Axis

Background

Hypoxia is an important process that involved in the tumor microenvironment. In addition, hypoxic tumor cell-derived exosomes could promote tumor growth and angiogenesis. Thus, we aimed to investigate whether exosomes could regulate tumor development and progression under hypoxia in breast cancer.

Methods

The level of SNHG1 in hypoxic breast cancer cells and exosomes derived from hypoxic breast cancer cells was determined by real-time qPCR assay. Bioinformatics prediction and dual-luciferase reporter assays were used to determine the interaction between SNHG1, miR-216b-5p and JAK2.

Results

We found that comparing with exosomes derived from normoxia breast cancer cells, exosomes derived from hypoxic breast cancer cells could promote the proliferation, migration and angiogenesis of human umbilical vein endothelial cells (HUVECs). In addition, SNHG1 level was significantly upregulated in exosomes derived from hypoxic breast cancer cells. Moreover, exosome-mediated delivery of SNHG1 siRNA3 markedly reversed the effects of exosome-mediated delivery of SNHG1 on HUVECs. Mechanically, SNHG1 could increase the level of JAK2 by competitively binding to miR-216b-5p. Additionally, exosome-mediated delivery of SNHG1 was found to promote breast cancer growth in vivo.

Conclusion

Collectively, our study revealed that exosomal SNHG1 from hypoxic breast cancer cells could promote tumor angiogenesis and growth via regulating miR-216b-5p/JAK2 axis, suggesting that SNHG1 may serve as a potential therapeutic target for breast cancer.

DPF3, A Putative Candidate Gene For Melanoma Etiopathogenesis in Gray Horses

Melanoma prevalence in gray horses reaches up to 50% and more. Several studies have documented a genetic melanoma predisposition which is referred to the 4.6 kb duplication in intron 6 of STX17 and its surrounding haplotype. However, the genetic background and mechanisms responsible for differences in etiopathogenesis of equine dermal melanomatosis still remain unknown. In the current study, we performed a genome wide association analysis in 141 Lipizzan horses and subsequently identified one candidate gene on chromosome 24 putatively involved in melanoma pathogenesis in gray horses. The associated SNP was located in the intronic region of DPF3, a gene which is involved in humans in cell growth, proliferation, apoptosis and motility of cancer cells. The replication study in 1210 horses from seven breeds demonstrated, that the G/G genotype of the DPF3 associated SNP exhibits putative melanoma suppression effects. As a conclusion DPF3 represents a candidate gene, which might play an essential role for gray horses coping with high genetic melanoma related tumor load.

Revealing New Candidate Genes for Teat Number Relevant Traits in Duroc Pigs Using Genome-Wide Association Studies

Simple Summary

Number of teats is very important for lactating sows. We conducted genome-wide association studies (GWAS) and estimated the genetic parameters for traits related to teat number. Results showed that there were nine and 22 SNPs exceeding genome-wide significance and suggestive significance levels, respectively. Eighteen genes annotated near them were concentrated on chromosomes 7 and 10. Among them, three new candidate genes were located on the genomic regions around the significant SNPs. Our findings provide new insight into investigating the complex genetic mechanism of traits related to teat number in pigs.

Abstract

The number of teats is related to the nursing ability of sows. In the present study, we conducted genome-wide association studies (GWAS) for traits related to teat number in Duroc pig population. Two mixed models, one for counted and another for binary phenotypic traits, were employed to analyze seven traits: the right (RTN), left (LTN), and total (TTN) teat numbers; maximum teat number on a side (MAX); left minus right side teat number (LR); the absolute value of LR (ALR); and the presence of symmetry between left and right teat numbers (SLR). We identified 11, 1, 4, 13, and 9 significant SNPs associated with traits RTN, LTN, MAX, TTN, and SLR, respectively. One significant SNP (MARC0038565) was found to be simultaneous associated with RTN, LTN, MAX and TTN. Two annotated genes (VRTN and SYNDIG1L) were located in genomic region around this SNP. Three significant SNPs were shown to be associated with TTN, RTN and MAX traits. Seven significant SNPs were simultaneously detected in two traits of TTN and RTN. Other two SNPs were only identified in TTN. These 13 SNPs were clustered in the genomic region between 96.10—98.09 Mb on chromosome 7. Moreover, nine significant SNPs were shown to be significantly associated with SLR. In total, four and 22 SNPs surpassed genome-wide significance and suggestive significance levels, respectively. Among candidate genes annotated, eight genes have documented association with the teat number relevant traits. Out of them, DPF3 genes on Sus scrofa chromosome (SSC) 7 and the NRP1 gene on SSC 10 were new candidate genes identified in this study. Our findings demonstrate the genetic mechanism of teat number relevant traits and provide a reference to further improve reproductive performances in practical pig breeding programs.

Stress-induced phosphoprotein 1 facilitates breast cancer cell progression and indicates poor prognosis for breast cancer patients

Breast cancer (BC) threatened the life health of a tremendous amount of the population, and the estimated number of death is still rising nowadays. We found that stress-induced phosphoprotein 1 (STIP1) is overexpressed in BC tissues compared to non-tumorous breast tissues. Our study is to validate the prognostic value of STIP1 and investigate its biological role in BC. We verified the upregulation of STIP1 in multiple databases, proved that STIP1 is upregulated in BC tissues and cell lines using real-time quantitative PCR (qRT-PCR). We used small interfering RNA to examine the function of STIP1 in BC cell lines (BT-549, MDA-MB-231, Hs-578 T) and explored the mechanism of function of STIP1 in BC cells using Western blotting and qRT-PCR. Analyses of multiple databases indicated that high STIP1 expression is a marker that effectively distinguishes BC patients from healthy control and predicts worse clinical outcomes in BC. The loss-of-function experiments showed that STIP1 silencing results in inhibition of cell proliferation and migration, inducing cell apoptosis, and S-phase arrest in vitro. Our study also showed that STIP1 downregulation inhibited the JAK2/STAT3 pathway and epithelial-mesenchymal transition process. Rescue experiments demonstrated that the oncogenic effect of STIP1 is partially dependent on mediating JAK2 expression. This study verified that STIP1 is an oncogenic gene that promotes BC progression and serves as a valuable diagnostic and outcome-related marker of BC.

DNA Methylation Clusters and Their Relation to Cytogenetic Features in Pediatric AML

Acute Myeloid Leukemia (AML) is characterized by recurrent genetic and cytogenetic lesions that are utilized for risk stratification and for making treatment decisions. In recent years, methylation dysregulation has been extensively studied and associated with risk groups and prognosis in adult AML, however, such studies in pediatric AML are limited. Moreover, the mutations in epigenetic genes such as DNMT3A, IDH1 or IDH2 are almost absent or rare in pediatric patients as compared to their abundance in adult AML. In the current study, we evaluated methylation patterns that occur with or independent of the well-defined cytogenetic features in pediatric AML patients enrolled on multi-site AML02 clinical trial (NCT00136084). Our results demonstrate that unlike adult AML, cytosine DNA methylation does not result in significant unique clusters in pediatric AML, however, DNA methylation signatures correlated significantly with the most common and recurrent cytogenetic features. Paired evaluation of DNA methylation and expression identified genes and pathways of biological relevance that hold promise for novel therapeutic strategies. Our results further demonstrate that epigenetic signatures occur complimentary to the well-established chromosomal/mutational landscape, implying that dysregulation of oncogenes or tumor suppressors might be leveraging both genetic and epigenetic mechanisms to impact biological pathways critical for leukemogenesis.

The DPF Domain As a Unique Structural Unit Participating in Transcriptional Activation, Cell Differentiation, and Malignant Transformation

The DPF (double PHD finger) domain consists of two PHD fingers organized in tandem. The two PHD-finger domains within a DPF form a single structure that interacts with the modification of the N-terminal histone fragment in a way different from that for single PHD fingers. Several histone modifications interacting with the DPF domain have already been identified. They include acetylation of H3K14 and H3K9, as well as crotonylation of H3K14. These modifications are found predominantly in transcriptionally active chromatin. Proteins containing DPF belong to two classes of protein complexes, which are the transcriptional coactivators involved in the regulation of the chromatin structure. These are the histone acetyltransferase complex belonging to the MYST family and the SWI/SNF chromatin-remodeling complex. The DPF domain is responsible for the specificity of the interactions between these complexes and chromatin. Proteins containing DPF play a crucial role in the activation of the transcription of a number of genes expressed during the development of an organism. These genes are important in the differentiation and malignant transformation of mammalian cells.

Exosomes: Insights from Retinoblastoma and Other Eye Cancers

Exosomes, considered as cell debris or garbage bags, have been later characterized as nanometer-sized extracellular double-membrane lipid bilayer bio-vesicles secreted by the fusion of vesicular bodies with the plasma membrane. The constituents and the rate of exosomes formation differ in different pathophysiological conditions. Exosomes are also observed and studied in different parts of the eye, like the retina, cornea, aqueous, and vitreous humor. Tear fluid consists of exosomes that are shown to regulate various cellular processes. The role of exosomes in eye cancers, especially retinoblastoma (RB), is not well explored, although few studies point towards their presence. Retinoblastoma is an intraocular tumor that constitutes 3% of cases of cancer in children. Diagnosis of RB may require invasive procedures, which might lead to the spread of the disease to other parts. Due to this reason, better ways of diagnosis are being explored. Studies on the exosomes in RB tumors and serum might help designing better diagnostic approaches for RB. In this article, we reviewed studies on exosomes in the eye, with a special emphasis on RB. We also reviewed miRNAs expressed in RB tumor, serum, and cell lines and analyzed the targets of these miRNAs from the proteins identified in the RB tumor exosomes. hsa-miR-494 and hsa-miR-9, upregulated and downregulated, respectively in RB, have the maximum number of targets. Although oppositely regulated, they share the same targets in the proteins identified in RB tumor exosomes. Overall this review provides the up-to-date progress in the area of eye exosome research, with an emphasis on RB.

Role of STAT3 signaling pathway in breast cancer

Breast cancer has grown to be the second leading cause of cancer-related deaths in women. Only a few treatment options are available for breast cancer due to the widespread occurrence of chemoresistance, which emphasizes the need to discover and develop new methods to treat this disease. Signal transducer and activator of transcription 3 (STAT3) is an early tumor diagnostic marker and is known to promote breast cancer malignancy. Recent clinical and preclinical data indicate the involvement of overexpressed and constitutively activated STAT3 in the progression, proliferation, metastasis and chemoresistance of breast cancer. Moreover, new pathways comprised of upstream regulators and downstream targets of STAT3 have been discovered. In addition, small molecule inhibitors targeting STAT3 activation have been found to be efficient for therapeutic treatment of breast cancer. This systematic review discusses the advances in the discovery of the STAT3 pathways and drugs targeting STAT3 in breast cancer. Video abstract.