PIK3CA-mutations in breast cancer

Reinhardt, Kristin; Stückrath, Kathrin; Hartung, Carolin; Kaufhold, Sandy; Uleer, Christoph; Hanf, Volker; Lantzsch, Tillmann; Peschel, Susanne; John, Jutta; Pöhler, Marleen; Bauer, Marcus; Bürrig, Friedrich Karl; Weigert, Edith; Buchmann, J; Kantelhardt, Eva Johanna; Thomssen, Christoph; Vetter, Martina

doi:10.1007/s10549-022-06637-w

Cited by 43 publications

(29 citation statements)

References 42 publications

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“…In summary, the data obtained with ZeptoChip detection and true single cell lysates were well in accordance with western blot analysis measured from more than 2x10 6 -fold starting cell material and support that the established workflow is highly sensitive and able to measure both the expression and functional (phosphorylation) status of signaling protein markers in parallel from single cells and in a multiplex format.…”

Section: Measuring Phosphorylation Of Akt In Single Tumor Cell Line C...supporting

confidence: 79%

“…To this aim, CTCs are isolated and further characterizeddue to their stabilitymainly at the level of their genomic DNA to uncover DNA mutations and aberrations informing us about potential targeted treatment options (4). Some frequently detected -hence called -hotspot mutations are known for e.g., genes such as AKT1, PIK3CA, and ESR1, reaching frequencies between 2% to 40% in breast cancer (5)(6)(7). Such hotspot mutations, which mostly result in over-activated protein products drive the progression of tumor disease and the expansion of metastasizing tumor subclones.…”

Section: Introductionmentioning

confidence: 99%

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ZeptoCTC - Sensitive Protein Analysis of True Single Cell Lysates using Reverse Phase Protein Arrays (RPPA)

Rivandi,

Franken,

Yang

et al. 2023

Preprint

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Circulating Tumor Cells (CTCs) are commonly analyzed through genomic profiling, which does not capture posttranslational and functional alterations of encoded proteins. To address this limitation, we developed ZeptoCTC, a single-cell protein analysis workflow that combines established technologies for single-cell isolation and sensitive Reverse Phase Protein Array (RPPA) analysis to assess multiple protein expression and activation in individual CTCs. The workflow involves single cell labeling, isolation, lysis, and printing of the true single cell lysates onto a ZeptoChip using a modified micromanipulator CellCelector™. Subsequently, the printed lysates undergo fluorescence immunoassay RPPA protein detection using a ZeptoReader followed by signal quantification with Image J software. ZeptoCTC was successfully optimized, beginning with the measurement of EpCAM protein expression, a standard marker for CTC detection. As expected, mean fluorescence signals for EpCAM levels were significantly higher in single MCF-7 cells compared to MDA-MB-231 cells. Next, Capivasertib-treated MCF-7 cells exhibited an approximately 2-fold increase in the pAkt/Akt ratio compared to non-treated control cells. This finding was consistent with a co-performed western blot analysis of pooled MCF-7 cells. Application of ZeptoCTC to the analysis of single CTCs derived from a metastasized breast cancer (MBC) patient indicated a significantly higher level of pAkt, accompanied by a corresponding increase in pErk level when compared to patient-matched WBC. Finally, the current workflow successfully indicated the detectable pAkt and Akt signal difference in CTCs from two MBC patients: one with an Akt1 wild-type genotype, and the other harboring approximately 80% Akt1(E17K) mutated CTCs. The mutated CTCs revealed clearly elevated pAkt levels (1.8-fold), along with an even more strongly elevated total Akt (3.4-fold) when compared to the respective signals measured in wild-type CTCs. In conclusion, ZeptoCTC is a highly sensitive method for measuring the expression and phosphorylation of treatment-relevant proteins in key cancer-driving signaling pathways from true single cell samples.

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Section: Measuring Phosphorylation Of Akt In Single Tumor Cell Line C...supporting

confidence: 79%

Section: Introductionmentioning

confidence: 99%

ZeptoCTC - Sensitive Protein Analysis of True Single Cell Lysates using Reverse Phase Protein Arrays (RPPA)

Rivandi,

Franken,

Yang

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…In an attempt to decrease the metabolism and target the His931 residue, the C3-nitrile analogue 12 was synthesized and provided a compound that was 3-fold more potent and 4-fold more stable in human hepatocytes (Cl int for 12: 79 mL/min/kg) than 8. Conversely, replacing the C3-nitrile in 12 with a trifluoromethyl (13) or an amide ( 14) resulted in a substantial loss in potency.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Discovery of Pyridopyrimidinones that Selectively Inhibit the H1047R PI3Kα Mutant Protein

Ketcham,

Harwood,

Aranda

et al. 2024

J. Med. Chem.

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The H1047R mutation of PIK3CA is highly prevalent in breast cancers and other solid tumors. Selectively targeting PI3Kα H1047R over PI3Kα WT is crucial due to the role that PI3Kα WT plays in normal cellular processes, including glucose homeostasis. Currently, only one PI3Kα H1047R -selective inhibitor has progressed into clinical trials, while three pan mutant (H1047R, H1047L, H1047Y, E542K, and E545K) selective PI3Kα inhibitors have also reached the clinical stage. Herein, we report the design and discovery of a series of pyridopyrimidinones that inhibit PI3Kα H1047R with high selectivity over PI3Kα WT , resulting in the discovery of compound 17. When dosed in the HCC1954 tumor model in mice, 17 provided tumor regressions and a clear pharmacodynamic response. X-ray cocrystal structures from several PI3Kα inhibitors were obtained, revealing three distinct binding modes within PI3Kα H1047R including a previously reported cryptic pocket in the C-terminus of the kinase domain wherein we observe a ligand-induced interaction with Arg1047.

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“…However, in earlier stage of disease the detected GAs may give valuable hints concerning possible ineffectiveness or relevant toxicity of certain therapies. In this context, Reinhardt et al screened 1270 patients with early breast cancer for the presence of PIK3CA mutations and found a significant influence on the effect of adjuvant aromatase inhibitors but no influence on the efficacy of adjuvant tamoxifen [18]. Similar to ESCAT a validated classification of these GAs is highly needed for clinical routine.…”

Section: Discussionmentioning

confidence: 99%

Whole Exome Analysis to Select Targeted Therapies for Patients with Metastatic Breast Cancer – A Feasibility Study

Jaeger,

Krawczyk,

Japp

et al. 2023

Geburtshilfe Frauenheilkd

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The purpose of this feasibility study was to select targeted therapies according to “ESMO Scale for Clinical Actionability of molecular Targets (ESCAT)”. Data interpretation was further supported by a browser-based Treatment Decision Support platform (MH Guide, Molecular Health, Heidelberg, Germany).We applied next generation sequencing based whole exome sequencing of tumor tissue and peripheral blood of patients with metastatic breast cancer (n = 44) to detect somatic as well as germline mutations.In 32 metastatic breast cancer patients, data interpretation was feasible. We identified 25 genomic alterations with ESCAT Level of Evidence I or II in 18/32 metastatic breast cancer patients, which were available for evaluation: three copy number gains in HER2, two gBRCA1, two gBRCA2, six PIK3CA, one ESR1, three PTEN, one AKT1 and two HER2 mutations. In addition, five samples displayed Microsatellite instability high-H.Resulting treatment options were discussed in a tumor board and could be recommended in a small but relevant proportion of patients with metastatic breast cancer (7/18). Thus, this study is a valuable preliminary work for the establishment of a molecular tumor board within the German initiative “Center for Personalized Medicine” which aims to shorten time for analyses and optimize selection of targeted therapies.

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PIK3CA-mutations in breast cancer

Cited by 43 publications

References 42 publications

ZeptoCTC - Sensitive Protein Analysis of True Single Cell Lysates using Reverse Phase Protein Arrays (RPPA)

ZeptoCTC - Sensitive Protein Analysis of True Single Cell Lysates using Reverse Phase Protein Arrays (RPPA)

Discovery of Pyridopyrimidinones that Selectively Inhibit the H1047R PI3Kα Mutant Protein

Whole Exome Analysis to Select Targeted Therapies for Patients with Metastatic Breast Cancer – A Feasibility Study

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