Tumoral load quantification of positive sentinel lymph nodes in breast cancer to predict more than two involved nodes

AimOne-Step Nucleic Acid Amplification (OSNA) can detect isolated tumour loads in axillary lymph nodes of breast cancer patients. We investigated the predictability of the non-sentinel lymph node (SLN) metastatic involvement (MI) based on the OSNA SLN assessment in surgical invasive breast cancer.MethodsWe studied surgical breast invasive carcinoma patients, not taking neoadjuvant chemotherapy, having SLN positive by OSNA and having received axillary lymphadenectomy. Age, basic histopathological, immunohistochemical, SLN biopsy and lymphadenectomy data were compared between patients with or without MI of more than 2 non-SLN in both univariate and multivariate analyses. The discriminating capacity of the multivariate model was characterized by the ROC AUC.Results726 patients from 23 centers in Spain aged 55.3 ± 12.2 years were analysed. The univariate analysis comparing patients with or without MI of more than 2 non-SLN detected statistically significant differences in primary tumour size, multifocality, presence of lymphovascular infiltration, positive proliferation index with ki67, immunophenotype and logTTL (Tumour Total Load). The multivariate logistic analyses (OR (95% CI)) confirmed multifocality (2.16 (1.13–4.13), p = 0.019), lymphovascular infiltration (4.36 (2.43–7.82), p < 0.001) and logTTL (1.22 (1.10–1.35), p < 0.001) as independent predictors, and exhibit an AUC (95% CI) of 0.78 (0.72–0.83) with an overall fit (Hosmer–Lemeshow test) of 0.359. A change in the slope of both sensitivity and specificity is observed at about 10,000 copies/μL, without relevant changes in the Negative Predictive Values.ConclusionsUsing OSNA technique, the MI of more than 2 non-SLN can be reliably predicted.     

Ultra-micro samples can be used for mRNA quantification of lung cancer biomarkers

Background Isolating sufficient material for molecular testing remains challenging in non-small cell lung cancer (NSCLC). The use of new ultra-microsamples (uMS) is proven sufficient for DNA and mRNA detection, but whether uMS are useful for quantifying mRNA expression is unknown. We investigated if uMS from lung cancer patients can be used to generate quantitative data on mRNA expression. Methods uMS were collected from primary tumors and lymph nodes from patients suspected of having lung cancer. mRNA was isolated, reverse-transcribed into cDNA and quantified with quantitative PCR assays for hepatocyte growth factor receptor (MET), hepatocyte growth factor (HGF), epidermal growth factor receptor (EGFR) and amphiregulin (AREG) mRNA. The fraction of tumor cells to normal cells was estimated in each sample. Results MET, HGF, EGFR, and AREG expression were evaluated in 90 samples (30 containing cancer cells and 60 without cancer cells). MET and EGFR expression were negligible in samples without cancer cells. In samples containing cancer cells, MET and EGFR could be quantified in 13 samples each. Adjustment for tumor-cell fraction made it possible to obtain a quantitative result for the tumor-cell mRNA expression of MET and EGFR. In contrast, AREG and HGF were expressed in samples without tumor cells. These samples were used to establish the AREG and HGF mRNA expression in normal cells. Seven out of 14?AR-positive and two out of eight HGF-positive samples with tumor cells were above a cut-off of the mean?+?2SD established in samples without tumor cells. Conclusion We demonstrate that uMS contain high-quality mRNA, and quantitative studies can be performed when the tumor-cell fraction is considered.     

牛蒡多糖对K562细胞增殖的抑制及其机制的探讨

目的研究牛蒡多糖对K562细胞增殖的抑制作用并初步探索其机制。方法 MTT法检测牛蒡多糖对K562细胞增殖的抑制作用,RT-PCR检测BCL-2mRNA、Bax mRNA的表达。结果牛蒡多糖能明显抑制K562细胞的增殖;BCL-2基因表达下调,Bax的基因表达增多。结论牛蒡多糖对K562细胞增殖有抑制作用,其机制可能与BCL-2基因表达下调,Bax的表达上调有关。     

Rotation of the head of the 30S ribosomal subunit during mRNA translocation

Elongation factor-G–catalyzed translocation of mRNA and tRNAs during protein synthesis involves large-scale conformational changes in the ribosome. Formation of hybrid-state intermediates is coupled to counterclockwise (forward) rotation of the body of the 30S subunit. Recent structural studies implicate intrasubunit rotation of the 30S head in translocation. Here, we observe rotation of the head during translocation in real time using ensemble stopped-flow FRET with ribosomes containing fluorescent probes attached to specific positions in the head and body of the 30S subunit. Our results allow ordering of the rates of movement of the 30S subunit body and head during translocation: body forward > head forward > head reverse ≥ body reverse. The rate of quenching of pyrene-labeled mRNA is consistent with coupling of mRNA translocation to head rotation.     

Separation of Elastin Components by Thin Layer Chromatography and Electrophoresis

Several methods are described which employ thin layer chromatography and electrophoresis for investigations into the structure and synthesis of crosslinked elastin. These procedures are more sensitive and involve less elaborate equipment than separation on paper. The methods described include an electrophoretic procedure for detecting the crosslinking amino acids in elastin hydrolysates, a method for completely separating desmosine, isodesmosine and merodesmosine in these hydrolysates, and a method for producing two-dimensional peptide maps of elastase digests of elastin.     

Somatostatin receptor 1–5; expression profiles during rat development

Abstract

Background. Somatostatin acts through five receptor subtypes (SSTRs 1–5). We aimed to investigate SSTRs mRNA expression and protein distribution in whole rat embryos, with special emphasis on the pancreas.

Material and methods. Rat embryos were collected on embryonal days 10, 11, 12, 14, 15, 17, 19, 21, and at birth. Presence of SSTRs was investigated with RT-PCR techniques and immunohistochemistry.

Results. There was no SSTR5 mRNA expression in the whole rat embryos. All SSTR1–5 proteins were observed at embryonal day 10, but the localization varied between the different subtypes. From day 11 to birth SSTRs protein presence increased with time in major structures such as skin and cartilage. It remained similar over time in the heart and liver. In the fetal pancreas mRNA expression of SSTR2 and 4 was detected at day 14, and there was an increase up to birth. Only SSTR1 protein co-localized to a higher extent with the islet hormones studied. SSTR2 was present in all islet endocrine cells except for β-cells. In contrast, the immunostaining for SSTR3–4 was co-localized with insulin and PP, and, finally, SSTR5 with glucagon and pancreatic polypeptide. In mRNA isolated from whole rat embryos SSTR1-2 and SSTR4 expression showed a peak at day 14, while SSTR3 mRNA was not present until day 15.

Conclusion. The present data suggest a role for SSTRs during the development of the rat embryo. Subsequent functional studies may elucidate regulatory roles of specific SSTRs for the growth and differentiation of the pancreas as well as other organs.