Clinical Significance of the Epidermal Growth Factor Receptor and HER2 Receptor in Resectable Gastric Cancer

Background: Epidermal growth factor receptor (EGFR or HER1) and its homolog c-erbB-2 (HER2) are membrane receptors. Both EGFR and HER2 genes are overexpressed in a variety of solid human cancers and are related to poor prognosis of the patients. The objective of this work was to evaluate the EGFR and HER2 contents in resectable gastric cancer, their possible relationship with clinicopathologic parameters of tumors, and their prognostic significance.Methods: This was a prospective analysis of 63 patients with resectable gastric carcinomas, with a mean follow-up period of 40.7 months. Membranous EGFR levels were examined by radioligand binding assays, and cytosolic HER2 levels were examined by means of an immunoenzymatic assay.Results: There was a wide variability of EGFR (1–1,239 fmol/mg of protein) and HER2 (7–20,863 NHU/mg of protein) levels in tumors. There was no significant correlation between these levels and patient or tumor characteristics. However, high levels of EGFR and HER2 were significantly associated with a shorter overall survival period (P = .03 and P = .02, respectively).Conclusions: There is a wide variability in membranous EGFR levels and in cytosolic HER2 levels in gastric cancer, which seems to be related to the biological heterogeneity of these tumors. In addition, high tumor EGFR and HER2 levels were associated with an unfavorable outcome in patients with resectable gastric cancer.     

Characterization of breast cancer subtypes by quantitative assessment of biological parameters: relationship with clinicopathological characteristics, biological features and prognosis

Objectives

Gene expression analysis has identified several breast cancer subtypes, including luminal, epidermal growth factor receptor-2 positive (HER2+), and basal-like. To determine if our proposed molecular taxonomy correlates with biological and clinical behavior. This is based on four biological markers: estrogen and progesterone receptors (ER and PR, respectively), HER2 and the epidermal growth factor receptor-1 (HER1), all of them being determined by quantitative assays.

Study design

The biological parameters were examined by enzyme immunoassay, radioligand-binding assay or ELISA, in tumors from 787 patients with invasive breast cancer. Patients were prospectively evaluated over a median follow-up period of 50 months. Subtype definitions were as follows: luminal (ER+), HER2+ (HER2+, ER−, PgR−) and basal-like (HER2−, ER−, PgR−). In addition, we divided basal tumors into two groups based on their HER1 status.

Results

A 55.8% of tumors were of luminal type, 11.9% basal-like HER1+, 10.7 basal-like HER1−, and the remainder 21.6% HER2+. Both HER2+ and basal-like subtypes were more frequent in younger and premenopausal women, showing a higher percentage of cases of poorly differentiated tumors and higher S-phase fraction, when compared with those of luminal subtype. Multivariate analysis demonstrated that the subtype of tumor was related to both relapse and overall survival, being those of luminal subtype associated with the best prognosis.

Conclusions

Through the classification of breast tumors in four groups, according to their ER, PgR, HER2 and HER1 status, it is possible to obtain a major division of breast tumors associated with significant differences in biological features and clinical behavior.     

Cembrane diterpenes from the gorgonian Leptogorgia laxa

The new cembrane diterpenes leptodienone A (2) and leptodienone B (3) and the known compounds lopholide, lophodiol B, lophodione, and lophotoxin (1) have been isolated from the gorgonian Leptogorgia laxa collected in the Gulf of California. The structures of the new metabolites have been established by spectroscopic techniques. The in vitro cytotoxicity of the new compounds has been tested against three human tumor cell lines.     

Bioactive diterpenes and other constituents of Croton steenkampianus

A new indanone derivative (1) and two new diterpenoids (2 and 3), together with three known flavonoids, have been isolated from an ethanol extract of the leaves of Croton steenkampianus. The structure of 2 was solved by single-crystal X-ray diffraction analysis, whereas those of 1 and 3 were established mainly by 1D and 2D NMR spectroscopic methods. The isolated compounds were tested for their antiplasmodial activity and cytotoxicity. Antiplasmodial assays against chloroquine-susceptible strains (D10 and D6) and the chloroquine-resistant strains (Dd2 and W2) of Plasmodium falciparum showed that compound 2 gave moderate activities at 9.1-15.8 μM, while none of the compounds were cytotoxic against Vero cells.     

乙脑病毒 E蛋白的原核表达、纯化及初步鉴定

目的:构建乙脑病毒(JEV)E蛋白重组载体并在原核细胞BL21(DE3)中表达. 方法:采用RT-PCR扩增片段,定向克隆入pET28a( )中;重组载体pET28a-6His-E转化BL21(DE3),通过酶切、SDS-PAGE和Western Blotting检测其载体构建和蛋白表达;表达产物包涵体经Ni-NTA亲和层析纯化. 结果:构建得到原核融合重组载体pET28a-6His-E;诱导后表达得到6His-E融合蛋白,纯化得到表达产物并进行了初步的鉴定. 结论:表达并纯化得到JEV E蛋白原核表达产物.     

人OAZ-ORF2基因真核表达载体的构建及在Hela细胞中的表达

目的 克隆人鸟氨酸脱羧酶抗酶蛋白OAZ-ORF2基因,重组至真核表达载体,并在Hela细胞中表达.方法 以pET32a-OAZ质粒为模板,PCR法扩增OAZ-ORF2序列,测序鉴定后重组入真核表达载体pEGFP-N1,转染Hela细胞,表达重组蛋白.结果 PCR产物经琼脂糖电泳证实与目的基因长度一致,测序结果与GenBank公布的OAZ基因的ORF2序列一致.重组载体在Hela细胞中表达OAZ-ORF2蛋白,Western blotting分析在相对分子质量44.5×103左右出现新的蛋白条带.结论 成功构建人OAZ-ORF2基因真核表达载体,并获得表达.