The human oncogene PIK3CA is frequently mutated in human cancers. Two hotspot mutations in PIK3CA, E545K and H1047R, have been shown to regulate widespread signaling events downstream of AKT, leading to increased cell proliferation, growth, survival, and motility. We used quantitative mass spectrometry to profile the global phosphotyrosine proteome of isogenic knock-in cell lines containing these activating mutations, where we identified 824 unique phosphopeptides. Although it is well understood that these mutations result in hyperactivation of the serine/threonine kinase AKT, we found a surprisingly widespread modulation of tyrosine phosphorylation levels of proteins in the mutant cells. In the tyrosine kinome alone, 29 tyrosine kinases were altered in their phosphorylation status. Many of the regulated phosphosites that we identified were located in the kinase domain or the canonical activation sites, indicating that these kinases and their downstream signaling pathways were activated. Our study demonstrates that there is frequent and unexpected cross-talk that occurs between tyrosine signaling pathways and serine/threonine signaling pathways activated by the canonical PI3K-AKT axis.
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http://dx.doi.org/10.1021/acs.jproteome.5b00302 | DOI Listing |
Environ Toxicol
January 2025
Department of Medical Research, Chung Shan Medical University Hospital, Taichung, Taiwan.
The epithelial-mesenchymal transition (EMT) assists in the acquisition of invasiveness, relapse, and resistance in non-small cell lung cancer (NSCLC) and can be caused by the signaling of transforming growth factor-β1 (TGF-β1) through Smad-mediated or Smad-independent pathways. (-)-Epigallocatechin-3-gallate (EGCG), a multifunctional cancer-preventing bioconstituent found in tea polyphenols, has been shown to repress TGF-β1-triggered EMT in the human NSCLC A549 cell line by inhibiting the activation of Smad2 and Erk1/2 or reducing the acetylation of Smad2 and Smad3. However, its impact on the Smad-independent pathway remains unclear.
View Article and Find Full Text PDFAm J Med Genet A
January 2025
Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy.
TBCK (TBC1 Domain-Containing Kinase) encodes a protein playing a role in actin organization and cell growth/proliferation via the mTOR signaling pathway. Deleterious biallelic TBCK variants cause Hypotonia, infantile, with psychomotor retardation and characteristic facies 3. We report on three affected sibs, also displaying cardiac malformations.
View Article and Find Full Text PDFIUBMB Life
January 2025
Department of Reproductive Medical Center, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China.
Abnormality of granulosa cells (GCs) is the critical cause of follicular atresia in premature ovarian failure (POF). RIPK3 is highly expressed in GCs derived from atretic follicles. We focus on uncovering how RIPK3 contributes to ovarian GC senescence.
View Article and Find Full Text PDFImmunol Cell Biol
January 2025
Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, USA.
Natural killer (NK) cells are emerging agents for cancer therapy. Several different cytokines are used to generate NK cells for adoptive immunotherapy including interleukin (IL)-2, IL-12, IL-15 and IL-18 in solution, and membrane-bound IL-21. These cytokines drive NK cell activation through the integration of signal transducers and activators of transcription (STAT) and nuclear factor-kappa B (NF-κB) pathways, which overlap and synergize, making it challenging to predict optimal cytokine combinations for both proliferation and cytotoxicity.
View Article and Find Full Text PDFJ Transl Med
January 2025
Department of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, No. 1 Shuaifuyuan, Beijing, 100730, China.
Background: Immunotherapy is a significant risk factor for severe COVID-19 in multiple myeloma (MM) patients. Understanding how immunotherapies lead to severe COVID-19 is crucial for improving patient outcomes.
Methods: Human protein microarrays were used to examine the expression of 440 protein molecules in MM patients treated with bispecific T-cell engagers (BiTe) (n = 9), anti-CD38 monoclonal antibodies (mAbs) (n = 10), and proteasome inhibitor (PI)-based regimens (n = 10).
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