[Clinical and molecular predictors of response to EGFR tyrosine kinase inhibitors in non-small cell lung cancer]

Advance toward isolation, extraction, metabolism and health benefits of kaempferol, a major dietary flavonoid with future perspectives

As a major ubiquitous secondary metabolite, flavonoids are widely distributed in planta. Among flavonoids, kaempferol is a typical natural flavonol in diets and medicinal plants with myriad bioactivities, such as anti-inflammatory activity, anti-cancer activity, antioxidant activity, and anti-diabetic activity. However, the natural sources, absorption and metabolism as well as the bioactivities of kaempferol have not been reviewed comprehensively and systematically. This review highlights the latest research progress and the effect of kaempferol in the prevention and treatment of various chronic diseases, as well as its protective health effects, and provides a theoretical basis for future research to be used in nutraceuticals. Further, comparison of the different extraction and analytical methods are presented to highlight the most optimum for PG recovery and its detection in plasma and body fluids. Such review aims at improving the value-added applications of this unique dietary bioactive flavonoids at commercial scale and to provide a reference for its needed further development.

Prognostic value of expression of EGFR and nm23 for locoregionally advanced nasopharyngeal carcinoma

The purpose of this study was to evaluate the prognostic value of expression of EGFR and nm23 in patients with advanced-stage nasopharyngeal carcinoma (NPC). The study population comprised 127 patients with stage III-IVa NPC with sufficient pretreatment tumor biopsy specimens from 2003 to 2004 and clinical follow-up data. The expression of EGFR and nm23 was detected by immunohistochemistry. Survival analysis was performed using Kaplan-Meier method. The correlation between pretreatment expression of EGFR and nm23, and the effectiveness of chemoradiotherapy was analyzed. The EGFR expression was correlated with primary lesion stage and clinical stage (P = 0.001, 0.002, respectively). There was a statistically significant association between nm23 expression and local lymph node stage (P = 0.000). The positive EGFR expression had a higher recurrent rate than the negative (P = 0.015). The positive nm23 expression had a lower distant metastasis rate than the negative (P = 0.021). Negative expression of EGFR had a significantly better 5-year OS and DFS than positive expression (P = 0.015, 0.013, respectively). Positive expression of nm23 had a significantly higher 5-year OS and DFS than negative expression (P = 0.001, 0.006, respectively). Multivariate analysis indicated that both pretreatment EGFR and nm23 expression were strong independent factors for the overall survival of patients with NPC (P = 0.000, 0.000, respectively). Our data suggested that EGFR and nm23 can serve as reliable biomarkers for prognosis prediction in patients with NPC who may benefit from alternate treatment strategy and targeted treatment.

Coamplification at lower denaturation temperature-PCR increases mutation-detection selectivity of TaqMan-based real-time PCR

BACKGROUND

DNA genotyping with mutation-specific TaqMan(R) probes (Applied Biosystems) is broadly used in detection of single-nucleotide polymorphisms but is less so for somatic mutations because of its limited selectivity for low-level mutations. We recently described coamplification at lower denaturation temperature-PCR (COLD-PCR), a method that amplifies minority alleles selectively from mixtures of wild-type and mutation-containing sequences during the PCR. We demonstrate that combining COLD-PCR with TaqMan technology provides TaqMan genotyping with the selectivity needed to detect low-level somatic mutations.

METHODS

Minor-groove binder-based or common TaqMan probes were designed to contain a nucleotide that matches the desired mutation approximately in the middle of the probe. The critical denaturation temperature (T(c)) of each amplicon was then experimentally determined. COLD-PCR/TaqMan genotyping was performed in 2 steps: denaturation at the T(c), followed by annealing and extension at a single temperature (fast COLD-PCR). The threshold cycle was used to identify mutations on the basis of serial dilutions of mutant DNA into wild-type DNA and to identify TP53 (tumor protein p53) and EGFR [epidermal growth factor receptor (erythroblastic leukemia viral (v-erb-b) oncogene homolog, avian)] mutations in tumors.

RESULTS

COLD-PCR/TaqMan genotyping identified G>A mutations within TP53 exon 8 (codon 273 mutation hot spot) and C>T mutations within the EGFR gene (drug-resistance mutation T790M) with a selectivity improvement of 15- to 30-fold over regular PCR/TaqMan genotyping. A second round of COLD-PCR/TaqMan genotyping improved the selectivity by another 15- to 30-fold and enabled detection of 1 mutant in 2000 wild-type alleles. Use of COLD-PCR/TaqMan genotyping allowed quantitative identification of low-level TP53 and T790 mutations in colon tumor samples and in non-small-cell lung cancer cell lines treated with kinase inhibitors.

CONCLUSIONS

The major improvement in selectivity provided by COLD-PCR enables the popular TaqMan genotyping method to become a powerful tool for detecting low-level mutations in clinical samples.

Molecular pathology--translating research into clinical practice: an expanding frontier in surgical oncology

Molecular assays have now become essential to the pathologist and clinician alike in diagnosing and managing disease. This article highlights the techniques and molecular targets no longer ancillary to basic research. Ripe for discussion are the likely future impact of genetics on clinical care, the potential models for service provision, and the broader ethical, legal, and social issues related to the use of genetic information for nonmedical purposes. Molecular methods are forecasted to increase in assisting in the diagnosis of human diseases. The author's mission is to embrace this discipline and use these technologies in clinical practice.