Episomal lentiviral vectors confer erythropoietin expression in dividing cells.

Lentiviral vectors are now widely considered as one of the most common gene delivery tools for dividing and non-dividing cells. However, insertional mutagenesis has been found in clinical trials with retroviral vectors, which poses a safety risk. The use of non-integrating lentiviral (NIL) vectors, which avoid integration, eliminates the insertional mutagenesis problem. These NIL vectors are unable to mediate stable gene delivery into dividing cells, which makes them of limited use in the clinical practice of gene therapy. In this study, we constructed a NIL vector which harbors the scaffold/matrix attachment region (S/MAR) sequence and a therapeutic gene. NIL retained episomal erythropoietin (EPO) gene expression for 74days in dividing cells both with and without selection. Furthermore, Southern blot analysis showed that the NIL vector was retained extrachromosomally in CHO cells. In conclusion, the NIL vector based on an S/MAR sequence retained the extrachromosomal expression of a therapeutic gene in dividing cells. Our results show that NIL vectors maybe a safe and effective means of gene delivery, which is of potential clinical significance.

Plasma D-dimer value as a predictor of malignant lymph node involvement in operable non-small cell lung cancer.

Fibrin deposition and remodelling of the extracellular matrix are important early steps in tumour metastasis. The D-dimer value is an indicator of intravascular fibrin formation and degradation. Thus, the D-dimer value may be a predictor of the malignant involvement of lymph nodes in operable non-small cell lung cancer (NSCLC) patients. The study comprised 142 highly suspected lung cancer patients scheduled to undergo pneumonectomy, lobectomy or wedge resection. Of the 142 patients, 124 were subsequently diagnosed as NSCLC, and 18 were subsequently diagnosed as benign lung disease by histological examination. Preoperative plasma D-dimer values were quantified, and the relationship between plasma D-dimer and clinical variables including tumour size, involvement of lymph nodes and clinical stage was examined using Spearman correlation coefficients and χ (2) tests. The median plasma D-dimer values were statistically higher in NSCLC patients with malignant lymph nodes than in those who suffered either benign lung disease or carcinoma in situ (Kruskal-Wallis test; P = 0.001). Plasma D-dimer values were significantly correlated with clinical stage (ANOVA; P = 0.009). An obvious relationship was observed between elevated D-dimer (>0.475 mg/L fibrinogen equivalent units) and malignant lymph node involvement (χ (2) test; P = 0.0000). This correlation suggests that the plasma D-dimer value is a clinically important predictor for the malignant involvement of lymph nodes in operable NSCLC.

CAG repeats in the androgen receptor gene are shorter in patients with pulmonary, esophageal or bladder carcinoma and longer in women with uterine leiomyoma.

Preferential occurrence of pulmonary, esophageal and bladder carcinomas in males indicate a possible involvement of androgen receptor (AR)-mediated functions. We evaluated the roles of the CAG repeat polymorphism in AR exon 1 in development of these lesions. The exon 1 of AR gene was amplified in samples from 198 male patients with lung carcinoma, 183 with esophageal carcinoma, 95 with bladder carcinoma and 94 males with appendicitis, as a reference group. Mean numbers of the CAG repeat in these 3 cancer groups were determined to be 20.2, 20.0 and 20.0, respectively, all being significantly smaller than that of the reference group (21.1; P<0.05). Samples from 118 female patients with lung carcinoma and 154 females with appendicitis, as a reference group, were examined, with the mean CAG repeat number significantly smaller (19.8) than that of the female reference group (20.7; P<0.01). Samples from 108 patients with uterine leiomyoma were also examined, and their CAG repeat numbers were found to be markedly expanded (23.4; P<0.01). The patients with multiple leiomyomas tend to carry a longer CAG repeat structure, with the mean CAG repeat number longer in the multicentric multiple cases (24.1) compared to that of the unicentric, multinodular cases (22.2) and those with solitary lesions (23.1; P<0.01). These results indicate that a shorter CAG repeat structure may predispose individuals to a higher risk to some male-predominant neoplasms including pulmonary, esophageal and bladder carcinomas and a longer one confers women greater susceptibility to leiomyoma development in the uterus.