Breast cancer stem cells (CSCs) are resistant to most cancer therapeutics and contribute to tumor recurrence and metastasis. Two breast CSC-promoting transcription factors, truncated glioma-associated oncogene homolog 1 (tGLI1) and signal transducer and activator of transcription 3 (STAT3), have been reported to be frequently co-expressed in HER2-enriched breast cancer and triple-negative breast cancer (TNBC), undergo protein-protein interactions for gene regulation and activation, and functionally cooperate to promote breast CSCs. STAT3 can be activated by activated interleukin-6 receptor/glycoprotein-130 (IL-6R/GP130).
View Article and Find Full Text PDFInterleukin-1 Receptor Associated Kinase 1 (IRAK1) is a serine/threonine kinase that plays a critical role as a signaling transducer of the activated Toll-like receptor (TLR)/Interleukin-1 receptor (IL-1R) signaling pathway in both immune cells and cancer cells. Upon hyperphosphorylation by IRAK4, IRAK1 forms a complex with TRAF6, which results in the eventual activation of the NF-κB and MAPK pathways. IRAK1 can translocate to the nucleus where it phosphorylates STAT3 transcription factor, leading to enhanced IL-10 gene expression.
View Article and Find Full Text PDFBreast cancer is the most frequent malignancy in women, constituting 15.2% of all new cancers diagnosed in the United States. Distant breast cancer metastasis accounts for the majority of breast cancer-related deaths; brain metastasis is the third most common site for metastatic breast cancer but is associated with worst prognosis of approximately eight months of survival.
View Article and Find Full Text PDFHER2-positive and triple-negative breast cancers (TNBC) are difficult to treat and associated with poor prognosis. Despite showing initial response, HER2-positive breast cancers often acquire resistance to HER2-targeted therapies, and TNBC lack effective therapies. To overcome these clinical challenges, we evaluated the therapeutic utility of co-targeting TrkA and JAK2/STAT3 pathways in these breast cancer subtypes.
View Article and Find Full Text PDFProtein tyrosine phosphatase nonreceptor type 22 (PTPN22) is encoded by a major autoimmunity gene and is a known inhibitor of T cell receptor (TCR) signaling and drug target for cancer immunotherapy. However, little is known about PTPN22 posttranslational regulation. Here, we characterize a phosphorylation site at Ser situated C terminal to the catalytic domain of PTPN22 and its roles in altering protein function.
View Article and Find Full Text PDF