The role of protein inhibitor of activated STAT3 and miRNA-18a expressions in breast cancer

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.

Signaling pathways modulated by miRNAs in breast cancer angiogenesis and new therapeutics

MicroRNAs (miRNAs) act as oncogenes or tumor suppressors by suppressing the expression of target genes, some of which are engaged in angiogenic signaling pathways directly or indirectly. Tumor development and metastasis are dependent on angiogenesis, and it is the main reason for the poor prognosis of cancer patients. New blood vessels are formed from pre-existing vessels when angiogenesis occurs. Thus, it is essential to develop primary tumors and the spread of cancer to surrounding tissues. MicroRNAs (miRNAs) are small noncoding RNAs involved in various biological processes. They can bind to the 3'-UTR of their target genes and prevent them from expressing. MiRNAs control the activity of endothelial cells (ECs) through altering many biological pathways, which plays a key role in cancer progression and angiogenesis. Recent findings revealed that tumor-derived extracellular vesicles participated directly in the control of tumor angiogenesis by delivering miRNAs to ECs. miRNAs recently show great promise in cancer therapies to inhibit angiogenesis. In this study, we showed the miRNA-regulated signaling pathways in tumor angiogenesis with highlighting the anti-angiogenic therapy response and miRNA delivery methods that have been used to inhibit angiogenesis in both in vivo and in vitro studies.

Expression Analysis of Protein Inhibitor of Activated STAT in Inflammatory Demyelinating Polyradiculoneuropathy

Protein inhibitors of activated STAT (PIAS) are involved in the regulation of the JAK/STAT signaling pathway and have interactions with NF-κB, p73 and p53. These proteins regulate immune responses; therefore dysregulation in their expression leads to several immune-mediated disorders. In the present study, we examined expression of PIAS1-4 in peripheral blood of patients with acute/chronic inflammatory demyelinating polyradiculoneuropathy (AIDP/CIDP) compared with healthy subjects. We demonstrated down-regulation of all PIAS genes in both AIDP and CIDP cases compared with controls. Similarly, comparisons in gender-based groups revealed down-regulation of these gene0s in patients of each gender compared with gender-matched controls. There was no significant difference in expression of PIAS genes between AIDP and CIDP cases. Based on the area under the receiver operating characteristic curves, PIAS1-4 genes could distinguish between inflammatory demyelinating polyradiculoneuropathy and healthy status with accuracy values of 0.87, 0.87, 0.79 and 0.80, respectively. In differentiation between AIDP cases and healthy controls, these values were 0.92, 0.92, 0.83 and 0.86, respectively. Finally, PIAS1-4 genes could discriminate CIDP from healthy status with accuracy values of 0.82, 0.83, 0.75 and 0.75, respectively. The current study underscores the role of PIAS genes in the pathogenesis of inflammatory demyelinating polyradiculoneuropathy and their potential usage as biomarkers.