Feasibility and safety of modified retroperitoneal laparoscopic surgery in the treatment of upper urinary tract urothelial carcinoma / 中国内镜杂志

Objective?To evaluate the application of two kinds of retroperitoneal laparoscopic nephroureterectomy in upper urinary tract urothelial carcinoma and select the best operative approaches.?Methods?The clinical data of 40 cases of retroperitoneal laparoscopic surgery in patients with upper urinary tract tumor were analyzed. Among the 40 patients, 21 cases (14 males and 7 females) underwent modified retroperitoneal laparoscopic nephroureterectomy combined with transurethral incision of the ureteral orifice (group A), and 19 cases (13 males and 6 females) underwent retroperitoneal laparoscopic nephroureterectomy combined with hypogastrium minor incision and transurethral incision of the ureteral orifice (group B). The operative time, the blood loss, the retention time of drainage tube, the first exhaust time of postoperative and the hospital stay were compared between the two groups.?Results?The operation was successfully completed in all the 40 cases without conversion to open surgery. The operative time in group A was significantly shorter than that in group B (P < 0.01), and the hospital stay was significantly shorter than that in group B (P < 0.05). There were no statistical differences in blood loss, the retention time of drainage tube, and the first exhaust time of postoperative between the two groups (P > 0.05).?Conclusions?Compared with the retroperitoneal laparoscopic nephroureterectomy combined with hypogastrium minor incision, the modified retroperitoneal laparoscopic nephroureterectomy is safe and effective, which can shorten the operative time and reduce hospital saty. Tumor located in renal pelvis and the proximal &middle part of ureter, modified retroperitoneal laparoscopic nephroureterectomy combined with transurethral incision of the ureteral orifice is the most effective method.

MicroRNA-34c Suppresses Breast Cancer Migration and Invasion by Targeting GIT1.

Abnormal expression of microRNAs plays important role in tumor metastasis. Migration and invasion of cancer cells accord for the metastasis and deterioration of breast cancer. However, the regulatory role of microRNAs in the invasion and migration of breast cancer cells has not completely understood yet. Here we found that microRNA-34c (miR-34c) was significantly downregulated in metastatic tissue of breast cancer. In vitro study showed that miR-34c negatively regulated GIT1 protein expression by binding to the 3'UTR of GIT1 mRNA. Consistently, GIT1 protein expression was found upregulated significantly in metastatic breast cancer. Moreover, miR-34c overexpression suppressed the expression of GIT1 protein, and this effect was restored by AMO-miR-34c in breast cancer cells. Overexpression of miR-34c suppressed cell migration and invasion in both MCF-7 and MDA-MD-231 breast cancer cells. Furthermore, knockdown of endogenous GIT1 expression reduced the migration and invasion of both two breast cancer cells. Collectively, miR-34c downregulation in breast cancer cells resulted in the upregulation of GIT1, which in turn enhanced the migration and invasion of breast cancer. This study highlights molecular mechanism of migration and invasion of breast cancer cells.

Decrease of let-7f in low-dose metronomic Paclitaxel chemotherapy contributed to upregulation of thrombospondin-1 in breast cancer.

Low-dose metronomic (LDM) paclitaxel therapy displayed a stronger anti-angiogenic activity on breast tumors with fewer side effects. Upregulation of anti-angiogenic factor Thrombospondin-1 (TSP-1) accords for therapeutic potency of LDM paclitaxel, but its molecular mechanism has not been elucidated yet. microRNAs (miRNAs) have emerged as new important regulators of tumor growth and metastasis. Here, we hypothesize that miRNAs are involved in TSP-1 overexpression in paclitaxel LDM therapy of breast tumors. The miRNA profile of tumor tissues from control, LDM and MTD groups in 4T1 mouse breast cancer model was detected by microarray, and then verified by quantitative real-time PCR (qRT-PCR). Luciferase assay and western blot were employed to explore the mechanisms of miRNAs involved in this process. We found that let-7f, let-7a, miR-19b and miR-340-5p were reduced by >2 fold, and miR-543* and miR-684 were upregulated by at least 50% in paclitaxel LDM therapy. qRT-PCR verification revealed that let-7f level was reduced most significantly in LDM therapy. Computational prediction using TargetScan and miRanda suggested THBS1 which encodes TSP-1 as a potential target for let-7f. Luciferase activity assay further confirmed that let-7f may bind to 3'UTR of THBS1 gene and inhibit its activity. Moreover, forced expression of let-7f led to a decrease of TSP-1 at both mRNA and protein levels in MCF-7 cells. Contrastly, let-7f inhibition induced an increased expression of THBS1 mRNA and TSP-1 protein, but did not affect the proliferation and apoptosis of MCF-7 cells. Paclitaxel LDM therapy led to a decrease of let-7f and the elevation of TSP-1 protein expression in MCF-7 cells, while overexpression of let-7f may abolish LDM-induced the upregulation of TSP-1 in MCF-7 cells. In summary, let-7f inhibition contributed to the upregulation of TSP-1 in paclitaxel LDM therapy, independently of proliferation, cell cycle arrest and apoptosis of breast cancer. This study indicates let-7f as a potential therapeutic target for breast tumor.

Expression,Purification and Enzymatic Characterization of Klebsiella sp.Glycerol Dehydrogenase in E.coli / 中国生物工程杂志

The dhaD gene encoding glycerol dehydrogenase(GDH) from Klebsiella sp.was amplified,and was inserted into expression vector pET-28a(+),the plasmid pET-28a-dhaD was constructed and was transformed into Escherichia coli BL21(DE3).SDS-PAGE showed that the gene dhaD was expressed successfully in recombinant E.coli BL21.Then GDH was purified by Ni-NTA affinity chromatography,the results showed a single band about 39kDa on SDS-PAGE gel,and the specified activity was about 156U/mg.The special activity of GDH is 4.6-fold higher than that of unpurified and the activity recovery is 67.4%.The optimum reaction pH was 11.0,and the GDH activity have little changed when incubated in the buffer of pH7.0～11.0.The optimum reactive temperature was 30℃,and the GDH was more stable on the temperature of 25℃～45℃.The Km value was 0.54mmol/L and Vmax was 0.49 ?mol/ml?min in the glycerol.