Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Brain metastases constitute a challenge in the management of patients with HER2-positive breast cancer treated with anti-HER2 systemic therapies. Here we sought to define the repertoire of mutations private to or enriched for in HER2-positive brain metastases. Massively parallel sequencing targeting all exons of 254 genes frequently mutated in breast cancers and/or related to DNA repair was used to characterize the spatial and temporal heterogeneity of HER2-positive breast cancers and their brain metastases in six patients. Data were analyzed with state-of-the-art bioinformatics algorithms and selected mutations were validated with orthogonal methods. Spatial and temporal inter-lesion genetic heterogeneity was observed in the HER2-positive brain metastases from an index patient subjected to a rapid autopsy. Genetic alterations restricted to the brain metastases included mutations in cancer genes FGFR2, PIK3CA and ATR, homozygous deletion in CDKN2A and amplification in KRAS. Shifts in clonal composition and the acquisition of additional mutations in the progression from primary HER2-positive breast cancer to brain metastases following anti-HER2 therapy were investigated in additional five patients. Likely pathogenic mutations private to or enriched in the brain lesions affected cancer and clinically actionable genes, including ATR, BRAF, FGFR2, MAP2K4, PIK3CA, RAF1 and TP53. Changes in clonal composition and the acquisition of additional mutations in brain metastases may affect potentially actionable genes in HER2-positive breast cancers. Our observations have potential clinical implications, given that treatment decisions for patients with brain metastatic disease are still mainly based on biomarkers assessed in the primary tumor.
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PMID:Genetic heterogeneity and actionable mutations in HER2-positive primary breast cancers and their brain metastases. 2975 76

Brain metastasis (BM) is the primary contributor to mortality in non-small cell lung cancer (NSCLC) patients. Although the findings of NSCLC genetic sequencing studies suggest the potential for personalizing therapeutic approaches, the genetic profiles and underlying mechanisms of BM progression remain poorly understood. Here, we investigated the genetic profiles of brain metastases from NSCLC in six patients with primary tumors and corresponding BM samples via whole exome sequencing and targeted panel sequencing. We have demonstrated considerable genetic heterogeneity between primary lung cancer and corresponding brain metastases specimens. High-frequency mutations were found in NOTCH2,NOTCH2NL,FANCD2,EGFR, and TP53. Additionally, EGFR and TP53 consistently exhibited high frequencies of mutation between primary tumors and corresponding brain metastases. The implication is that most of the genetic alterations may be acquired or lost during malignant progression, and the stable EGFR and TP53 mutational status between paired primary tumors and metastatic sites confirms that most mutations detected on analysis of the primary tumor or metastases are sufficient for clinical decision-making, and suggest there is no need to re-biopsy recurrent tumors or metastases for most NSCLC patients.
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PMID:Characterization of genetic alterations in brain metastases from non-small cell lung cancer. 3018 53

To demonstrate the usefulness of complementary next-generation sequencing (NGS) and immunohistochemistry (IHC) counting, we analyzed 196 patients with non-small cell lung cancer who underwent surgical resection and adjuvant chemotherapy. Formalin-fixed, paraffin-embedded samples of adenocarcinoma (ADC), squamous cell carcinoma, and large cell carcinoma were used to prepare tissue microarrays and were examined by protein H-score IHC image analysis and NGS for oncogenes and proto-oncogenes and genes of tumor suppressors, immune checkpoints, epithelial-mesenchymal transition factors, tyrosine kinase receptors, and vascular endothelial growth factors. In patients with brain metastases, primary tumors expressed lower PIK3CA protein levels. Overexpression of p53 and a higher PD-L1 protein H-score were detected in patients who underwent surgical treatment followed by chemotherapy as compared with those who underwent only surgical treatment The absence of brain metastases was associated with wild-type sequences of genes EGFR, CD267, CTLA-4, and ZEB1. The combination of protein overexpression according to IHC and mutation according to NGS was rare (ie, represented by a very low percentage of concordant cases), except for p53 and vascular endothelial growth factor. Our data suggest that protein levels detected by IHC may be a useful complementary tool when mutations are not detected by NGS and also support the idea to expand this approach beyond ADC to include squamous cell carcinoma and even large cell carcinoma, particularly for patients with unusual clinical characteristics. Conversely, well-pronounced immunogenotypic features seemed to predict the clinical outcome after univariate and multivariate analyses. Patients with a solid ADC subtype and mutated genes EGFR, CTLA4, PDCD1LG2, or ZEB1 complemented with PD-L1 or p53 protein lower expression that only underwent surgical treatment who develop brain metastases may have the worst prognosis.
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PMID:Usefulness of complementary next-generation sequencing and quantitative immunohistochemistry panels for predicting brain metastases and selecting treatment outcomes of non-small cell lung cancer. 3021 56

AZD3759 is a tyrosine kinase inhibitor and has an encouraging future in treating brain metastases of non-small cell lung cancer. Here, we determined that AZD3759 suppressed the viability of HepG2 cells, a hepatoma cell line, and induced their apoptosis, suggesting a new therapeutic potential of AZD3759 in hepatocellular carcinoma (HCC) treatment. Furthermore, we found that the activation of p53-SMAD family member 4 (SMAD4) positive feedback loop was involved in the induction of bulks of apoptosis in HepG2 cells in response to AZD3759 treatment. In this positive feedback loop, p53 induced the expression of SMAD4 by directly promoting its transcription as shown by p53 could bind to SMAD4 promoter; SMAD4, in turn, promoted the nuclear translocation of p53, which increased the transcription of pro-apoptotic genes, including PUMA and BAX (two p53 target genes) and finally resulted in apoptosis. To the best of our knowledge, p53-induced SMAD4 transcription and SMAD4-determined the sub-location of p53 have not been reported. Taken together, our results demonstrated that AZD3759 might be an alternative strategy for HCC treatment and activating p53-SMAD4 positive feedback loop might enhance its therapeutic effects on HCC.
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PMID:AZD3759 induces apoptosis in hepatoma cells by activating a p53-SMAD4 positive feedback loop. 3059 63

Achieving an effective drug concentration in the brain is as important as targeting the right pathway when developing targeted agents for brain tumors. SAR405838 is a novel molecularly targeted agent that is in clinical trials for various solid tumors. Its application for tumors in the brain has not yet been examined, even though the target, the MDM2-p53 interaction, is attractive for tumors that could occur in the brain, including glioblastoma and brain metastases. In vitro and in vivo studies indicate that SAR405838 is a substrate of P-glycoprotein (P-gp). P-gp mediated active efflux at the blood-brain barrier plays a dominant role in limiting SAR405838 brain distribution. Even though the absence of P-gp significantly increases the drug exposure in the brain, the systemic exposure, including absorption and clearance processes, were unaffected by P-gp deletion. Model-based parameters of SAR405838 distribution across the blood-brain barrier indicate the CLout of the brain was approximately 40-fold greater than the CLin The free fraction of SAR405838 in plasma and brain were found to be low, and subsequent Kpuu values were less than unity, even in P-gp/Bcrp knockout mice. These results indicate additional efflux transporters other than P-gp and Bcrp may be limiting distribution of SAR405838 to the brain. Concomitant administration of elacridar significantly increased brain exposure, also without affecting the systemic exposure. This study characterized the brain distributional kinetics of SAR405838, a novel MDM2 inhibitor, to evaluate its potential in the treatment of primary and metastatic brain tumors. SIGNIFICANCE STATEMENT: This paper examined the brain distributional kinetics of a novel MDM2-p53 targeted agent, SAR405838, to see its possible application for brain tumors by using in vitro, in vivo, and in silico approaches. SAR405838 is found to be a substrate of P-glycoprotein (P-gp), which limits its distribution to the brain. Based on the findings in the paper, manipulation of the function of P-gp can significantly increase the brain exposure of SAR405838, which may give an insight on its potential benefit as a treatment for primary and metastatic brain cancer.
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PMID:Brain Distributional Kinetics of a Novel MDM2 Inhibitor SAR405838: Implications for Use in Brain Tumor Therapy. 3161 89


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