Angiogenesis is involved in maintaining normal physiological processes like embryonic development, wound healing, inflammation and reproduction. Pathogenesis of various diseases like diabetic retinopathy, rheumatoid arthritis and cancer are associated with imbalanced angiogenesis. Angiogenic stimulators and inhibitors act together for keeping angiogenic switch in balance. Recently, miRNAs have been found to regulate various stages of angiogenesis. miRNAs are 21-23 nucleotides long, single stranded, noncoding RNA molecules generated endogenously. miRNA's ability to target multiple genes within a signaling pathway makes them promising target for the development of second generation anti-angiogenesis drugs. This review was conceived with the notion of availability of specific and comprehensive knowledge about AngiomiRs at one place. This will facilitate the research in basic understanding and in the development of new drugs. In this review, we have summarized the biology and therapeutic potential of the miRNAs, which are involved in controlling angiogenesis process. In miRNA biology, we have provided the updated summary of miRNAs in the regulation of endothelial cells, showed role of miRNAs in the signaling pathways of angiogenesis and, discussed the gaps in complete knowledge of mechanism. We have also provided exclusive insights regarding therapeutic potential of these miRNAs, in angiogenesis related disorders. Additionally, we have discussed the challenges in miRNA based drug delivery and updated the current efforts in the development of miRNA delivery methods. Though much research is needed to discover the complete miRNA network regulating angiogenesis but once it is done, targeting miRNA may be considered as a potential candidate for therapeutic invention against angiogenesis related disorders.

Background Prostate cancer is the most common form of cancer in males and accounts for high cancer related deaths. Therapeutic advancement in prostate cancer has not been able to reduce the mortality burden of prostate cancer, which warrants further research. FRG1 which affects angiogenesis and cell migration in Xenopus, can be a potential player in tumorigenesis. In this study, we investigated the role of FRG1 in prostate cancer progression. Methods Immunohistochemistry was performed to determine FRG1 expression in patient samples. FRG1 expression perturbation was done to investigate the effect of FRG1 on cell proliferation, migration and invasion, in DU145, PC3 and LNCaP cells. To understand the mechanism, we checked expression of various cytokines and MMPs by q-RT PCR, signaling molecules by western blot, in FRG1 perturbation sets. Results were validated by use of pharmacological inhibitor and activator and, western blot. Results In prostate cancer tissue, FRG1 levels were significantly reduced, compared to the uninvolved counterpart. FRG1 expression showed variable effect on PC3 and DU145 cell proliferation. FRG1 levels consistently affected cell migration and invasion, in both DU145 and PC3 cells. Ectopic expression of FRG1 led to significant reduction in cell migration and invasion in both DU145 and PC3 cells, reverse trends were observed with FRG1 knockdown. In androgen receptor positive cell line LNCaP, FRG1 doesn’t affect any of the cell properties. FRG1 knockdown led to significantly enhanced expression of GM-CSF, MMP1, PDGFA and CXCL1, in PC3 cells and, in DU145, it led to higher expression of GM-CSF, MMP1 and PLGF. Interestingly, FRG1 knockdown in both the cell lines led to activation of p38 MAPK. Pharmacological activation of p38 MAPK led to increase in the expression of GM-CSF and PLGF in DU145 whereas in PC3 it led to enhanced expression of GM-CSF, MMP1 and CXCL1. On the other hand, inhibition of p38 MAPK led to reduction in the expression of above mentioned cytokines. Conclusion FRG1 expression is reduced in prostate adenocarcinoma tissue. FRG1 expression affects migration and invasion in AR negative prostate cancer cells through known MMPs and cytokines, which may be mediated primarily via p38 MAPK activation. Electronic supplementary material The online version of this article (10.1186/s12885-019-5509-4) contains supplementary material, which is available to authorized users.

Multiple molecular subtypes and distinct clinical outcomes in breast cancer, necessitate specific therapy. Moreover, despite the improvements in breast cancer therapy, it remains the fifth cause of cancer-related deaths, indicating the involvement of unknown genes. To identify novel contributors and molecular subtype independent therapeutic options, we report reduced expression of FRG1 in breast cancer patients, which regulates GM-CSF expression via direct binding to its promoter. Reduction in FRG1 expression enhanced EMT and increased cell proliferation, migration, and invasion, in breast cancer cell lines. Loss of FRG1 increased GM-CSF levels which activated MEK/ERK axis and prevented apoptosis by inhibiting p53 in an ERK-dependent manner. FRG1 depletion in the mouse model increased tumor volume, phospho-ERK, and EMT marker levels. The therapeutic potential of anti-GM-CSF therapy was evident by reduced tumor size, when tumors with decreased FRG1 were treated with anti-GM-CSF mAb. We found an inverse expression pattern of FRG1 and phospho-ERK levels in breast cancer patient tissues, corroborating the in vitro and mouse model-based findings. Our findings first time elucidate the role of FRG1 as a metastatic suppressor of breast cancer by regulating the GM-CSF/MEK-ERK axis.

Breast cancer is the most leading cause of cancer related deaths in women. Although combination of improved earlier detection and effective adjuvant therapies has dropped the breast cancer mortality, still different molecular subtypes, acquisition of quick drug resistance make it difficult to combat against this deadliest disease. So, an urging has to be compelled to inspect the additional players which are still unexplored in breast cancer. The focus of our lab is to find out novel molecules regulating cancer development and progression. In this process, we discovered the role of FRG1 in tumorigenesis. FRG1 (FSHD Region Gene 1) is an evolutionary conserved gene which is reported to have role in muscle development, angiogenesis, RNA biogenesis, F actin bundling. In our previous study, we first time reported the association of FRG1 with cancer. In this study, our key interest is to explore the molecular mechanism behind the differential expression of FRG1 in breast cancer. Here we started our study by exploring the expression of FRG1 in patient samples where we found reduced FRG1 expression in around 87% of breast cancer patients compared to their normal counterparts. Further, we also observed that FRG1 level was lower in triple negative breast cancer (TNBC) patients compared to Luminal A (hormone responsive) type. Similar trends of FRG1 expression was observed in Luminal A (ER+) cell line MCF7 and TNBC cell line MDAMB231. Therefore, we decided to evaluate the effect of perturbed FRG1 level in two breast cancer cell lines MCF7 (Luminal A) and MDAMB231 (TNBC). Knockdown of FRG1 in MCF7 cells led to increased cell proliferation, migration, colony formation and invasion; whereas ectopic FRG1 expression in MDAMB231 showed a reduction in these properties. Next, we investigated the signaling molecules associated with FRG1 and affected the above mentioned cellular properties. We observed low FRG1 expression in breast cancer cell line MCF7 resulted into activation of MEK/ERK pathway. Various EMT molecules like snail, slug, twist and tumor promoting cytokines such as IL1/8, growth factor like PDGFα/β was found to be up regulated in vitro due to reduction of FRG1. Similarly, FRG1 overexpression resulted into considerable downregulation of these EMT markers and cytokines. Furthermore, we found a rescue of these EMT molecules when ERK was inhibited or activated which confirmed that reduction in FRG1 in breast cancer cell lines activated ERK pathway which in turn upregulated the EMT molecules. Interestingly our data showed similar kind of trends irrespective of molecular subtypes of breast cancer cell lines. Also our study showed an activation of estrogen signaling in breast cancer due to the unliganded mechanism of estrogen receptor by FRG1. Thus, our study first time suggests that FRG1 level is important for breast cancer progression irrespective of molecular subtypes; but further understanding and characterization of signalling mechanisms and interacting partners are required to conclusively comment on its tumor suppressive role. Citation Format: Bratati Mukherjee, Ankit Tiwari, Manjusha Dixit. Novel tumor suppressor FRG1 reduces cancerous properties of breast cancer cell lines by regulating ERK pathway, irrespective of molecular subtypes [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5969.