Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0043346 (xeroderma pigmentosum)
 2,924 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gemcitabine (Gemzar; Eli Lilly and Company, Indianapolis, IN) and cisplatin are commonly used in the treatment of many solid tumors, although the impact of chemotherapy is limited in metastatic non-small cell lung cancer. However, in clinical practice, there is a minority of patients who can attain long-term survival. Upregulation of mRNA transcripts has been linked to chemoresistance, and in some instances, mRNA expression has been correlated with polymorphisms. Cisplatin resistance is directly linked to the nucleotide excision repair system, specifically to the transcription-coupled nucleotide excision repair pathway that involves genes that are deficient in rare inborn disorders such as Cockayne syndrome and xeroderma pigmentosum. Overexpression of ERCC1 correlates with poor survival in gemcitabine/cisplatin-treated non-small cell lung cancer patients. At the preclinical level, ERCC1 and XPD mRNA expression correlate with each other, and overexpression of XPD causes selective cisplatin resistance in human tumor cell lines. XPD polymorphisms have been associated with lower DNA repair capacity. In our experience, time to progression is significantly higher in gemcitabine/cisplatin-treated patients with the Lys751Gln genotype (9.6 months) than in those with the Lys751Lys genotype (4.2 months; P =.03). Other polymorphisms involved in parallel DNA repair systems may well provide the same information, indicating a high degree of biologic redundancy. The overexpression of the subunit M1 of ribonucleotide reductase (RRM1) has been linked to gemcitabine resistance in our retrospective assessment. Preliminary findings that a subset of gemcitabine/cisplatin-treated patients with low ERCC1 and RRM1 mRNA levels show a significantly longer survival and highlight the possibilities of individually tailored chemotherapy.
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PMID:Targeted therapy in combination with gemcitabine in non-small cell lung cancer. 1291 17

Cells from a patient with a DNA repair-deficiency disorder are anticipated to bear a large number of somatic mutations. Because such mutations occur independently in each cell, there is a high degree of mosaicism in patients' tissues. While major mutations that have been expanded in many cognate cells are readily detected by sequencing, minor ones are overlaid with a large depth of non-mutated alleles and are not detected. However, cell cloning enables us to observe such cryptic mutations as well as major mutations. In the present study, we focused on a fibroblastic cell line that is derived from a patient diagnosed with xeroderma pigmentosum (XP), which is an autosomal recessive disorder caused by a deficiency in nucleotide excision repair. By making a list of somatic mutations, we can expect to see a characteristic pattern of mutations caused by the hereditary disorder. We cloned a cell by generating an iPS cell line and performed a whole-exome sequencing analysis of the progenitor and its iPS cell lines. Unexpectedly, we failed to find causal mutations in the XP-related genes, but we identified many other mutations including homozygous deletion of GSTM1 and GSTT1. In addition, we found that the long arm of chromosome 9 formed uniparental disomy in the iPS cell line, which was also confirmed by a structural mutation analysis using a SNP array. Type and number of somatic mutations were different from those observed in XP patients. Taken together, we conclude that the patient might be affected by a different type of the disorder and that some of the mutations that we identified here may be responsible for exhibiting the phenotype. Sequencing and SNP-array data have been submitted to SRA and GEO under accession numbers SRP059858 and GSE55520, respectively.
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PMID:Whole-exome sequencing of fibroblast and its iPS cell lines derived from a patient diagnosed with xeroderma pigmentosum. 2669 16