A positive association between the PIK3CA (H1047R) mutation and the patients' age was first found, except for the negative relationship with the degree of tumor differentiation.
"Identification and Characterization of a Novel Constitutional PIK3CA Mutation in a Child Lacking the Typical Segmental Overgrowth of ""PIK3CA-Related Overgrowth Spectrum""."
"Identification and Characterization of a Novel Constitutional PIK3CA Mutation in a Child Lacking the Typical Segmental Overgrowth of ""PIK3CA-Related Overgrowth Spectrum""."
One metastatic sample with mutated KRAS also harbored a PIK3CA (H1047R) mutation. qPCR showed increased copy numbers of PIK3CA in 6 (33%) tumors, VEGFR1 in 0 (0%) tumors, VEGFR2 in 4 (22%) tumors, and VEGFR3 in 6 (33%) tumors.
Using in situ genetic lineage tracing and limiting dilution transplantation, we have unravelled the potential of PIK3CA(H1047R), one of the most frequent mutations occurring in human breast cancer, to induce multipotency during tumorigenesis in the mammary gland.
Interestingly, expression of Pik3ca(H1047R) in unipotent basal cells gave rise to luminal-like cells, while its expression in unipotent luminal cells gave rise to basal-like cells before progressing into invasive tumours.
Here we show that expression of PIK3CA(H1047R</span>) in lineage-committed basal Lgr5-positive and luminal keratin-8-positive cells of the adult mouse mammary gland evokes cell dedifferentiation into a multipotent stem-like state, suggesting this to be a mechanism involved in the formation of heterogeneous, multi-lineage mammary tumours.
Gene set enrichment analysis reveals a highly significant concordance of the genes differentially expressed in MCF-10A-H1047R cells and the established protein and RNA signatures of basal breast cancer.
This study proposed to investigate the relationship of PIK3CA somatic mutations, the most common activating mutations in human breast cancer (BC), and the efficacy of neoadjuvant chemotherapy (NCT).Using a novel liquid chip technology,PIK3CA DNA somatic mutations and HER2, PTEN, EGFR mRNA expression profiles were analyzed in formalin fixed paraffin embedded samples of 93 BC patients treated with epirubicin plus docetaxel NCT.PIK3CA mutations were found in 30 patients (32.3%), in which the point mutations of E542K, E545K, H1047L and H1047R were 4.3, 9.7, 4.3 and 14.0%respectively.
PIK3CA exon 9 mutations (Q546R, E542Q, E545K, E542K and E545D) were found in 10 tumor samples, exon 20 mutations (H1047L, H1047R, T1025T and G1049R) in 21, where only 1 tumor sample had two exon 20 mutations (T1025T and H1047R).
To model PIK3CA-activating mutations in late stages of cancer, we took advantage of the isogenic conversion of a PIK3CA-wild-type tumor into a PIK3CA H1047R-mutated tumor using the highly metastatic colorectal cancer cell line SW48.
Here, we utilize a three-dimensional (3D) culture model to address how interactions between autophagy and the phosphatidylinositol 3-kinase(PI3K)/Akt/mammalian target of rapamycin pathway impact the malignant behavior of cells carrying a tumor-derived, activating mutation in PI3K (PI3K-H1047R).
In this study, we report the development of a knock-in mouse model for breast cancer where the endogenous Pik3ca allele was modified to allow tissue-specific conditional expression of a frequently found Pik3ca(H1047R) (Pik3ca(e20H1047R)) mutant allele.
Whole-exome analysis of the Pik3ca(H1047R)-driven mammary tumors identified multiple mutations, including Trp53 mutations that appeared spontaneously during the development of adenocarinoma and spindle cell tumors.